Mr. Jiwen Zhang has served as the Company’s Chairman of the Board since March 29, 2023. In addition, Mr. Zhang serves as the Chair of the Strategic Committee.

Mr. Jiwen Zhang has served as Chairman and Chief Executive Officer of Weichai America, which focuses on researching and developing a full line of off-road natural gas engines and engine components, since February 2023. Weichai America is a wholly owned subsidiary of Weichai Power, a publicly traded company on the Hong Kong Stock Exchange and the Shenzhen Stock Exchange. Mr. Jiwen Zhang has over twenty years of experience in the engine industry. From January 2013 to December 2022, Mr. Jiwen Zhang served as President of Kohler Power Systems, a multinational company located in Wisconsin, which specialized in diesel and gaseous generators, responsible for oversight of the global business operations. Prior to this, Mr. Jiwen Zhang served as Managing Director Commercial of Fiat Powertrain APAC from September 2010 to December 2012, Vice President of Volvo Penta Region Asia from May 2002 to August 2010, and Customer Service General Manager of a Caterpillar distributor Lei Shing Hong machinery from September 1994 to April 2002.

Mr. Jiwen Zhang earned his EMBA from University of Texas at Arlington and Bachelor’s degree of Mechanical & Electrical Engineering from University of Science and Technology of China.

Mr. Jiwen Zhang brings to the Board extensive and effective leadership experience demonstrated through his executive and management roles at leading engine manufacturers.

Frank P. Simpkins has served as a director of the Company since July 13, 2017. Mr. Simpkins is the Chair of the Audit Committee and is also a member of the Nominating Committee and Strategic Committee.

Mr. Simpkins has over 25 years of executive management and financial experience. From June 2016 to December 2016, he served as Chief Financial Officer of Emerson Network Power, part of Emerson Electric Co., a publicly traded company on the New York Stock Exchange (the “NYSE”). From 2006 to 2015, Mr. Simpkins served as Vice President and Chief Financial Officer of Kennametal Inc., a publicly traded company on the NYSE and a global leader in the design and manufacture of engineered components, advanced materials and cutting tools. Prior to that role, Mr. Simpkins held various positions within Kennametal since 1995. Prior to Kennametal, he worked as a Manager for PricewaterhouseCoopers from 1986 to 1995.

Mr. Simpkins serves on the Board of Trustees at Seton Hill University, Greensburg and previously served on the Board of Trustees of Pennsylvania State University, New Kensington. On September 1, 2022, Mr. Simpkins joined the Advisory Board of Anovion, an advanced battery materials business in North America for synthetic graphite anode materials.

He holds a Bachelor of Science degree in Accounting from Pennsylvania State University. Mr. Simpkins qualifies as an “Audit Committee Financial Expert” under applicable SEC regulations and has substantial public-company reporting experience gained from his roles as Chief Financial Officer during his career.

Mr. Simpkins brings to the Board significant management experience, as well as his experience as a Chief Financial Officer.

Simon He has served as a Director of the Company since November 14, 2019. Mr. He is the Chair of the Compensation Committee and a member of the Audit Committee. 

Mr. He serves as Director, Financial Planning & Analysis for CytomX Therapeutics (“CytomX”), a NASDAQ-listed biotechnology company, since February 2021, and previously served as a Consultant to CytomX beginning in February 2020. Previously, Mr. He served as Director of Finance and Reporting for Blackthorn Therapeutics, a clinical-stage biotechnology company, from June 2019 to December 2019. Prior to that, Mr. He served as the Head of Finance at GenapSys, Inc. from 2018 until May 2019. From 2014 until 2018, Mr. He was the finance director of SciClone Pharmaceuticals, Inc., a NASDAQ-listed specialty pharmaceutical company with main operations in China. From January to June 2014, Mr. He served as Vice President of Finance and the Controller of Augmedix, Inc., a privately held technology-enabled medical documentation company. From October 2011 to December 2013, Mr. He was employed as Vice President of Finance at Baidu Leho.com, a private company backed by Baidu, a NASDAQ- listed company. From 2015 to 2020, Mr. He served as Director and Audit Committee Chairman of Fuling Global, Inc., a disposable serviceware and kitchenware manufacturer.

Mr. He earned his Bachelors of Science degree in Accounting from Beijing University of Technology in July 1992 and his Masters of Business Administration degree from University of Chicago Booth School of Business in December 2006. Mr. He is a U.S. certified management accountant and a China certified public accountant. Mr. He qualifies as an “Audit Committee Financial Expert” under applicable SEC regulations and has substantial public company reporting experience gained from his roles as a financial officer and controller of public companies during his career.

Mr. He brings to the Board substantial financial and managerial experience gained through leadership roles at public companies.

Fuzhang Yu has served as a director of the Company since July 2023. Mr. Yu is a member of the Compensation Committee.

Mr. Yu has served as Director of the Overseas Finance Department of Weichai Group since May 2023 and Vice Director from January 2023 to May 2023. Prior to that, Mr. Yu served as Chief Financial Official of Shaanxi Hande Axle Co., Ltd, a leading commercial vehicle axle manufacturer in China from February 2021 to January 2023. From February 2019 to February 2021, Mr. Yu served as Chief Financial Officer of Weichai Ballard Co., Ltd (“Weichai Ballard”), a joint venture of Weichai Power and Ballard Power Systems Inc. Prior to his role at Weichai Ballard, Mr. Yu served in various leadership roles in the Finance Department at Weichai Power from January 2009 to February 2019. 

Mr. Yu earned his Bachelor’s degree in management from Beijing Forestry University, China in 2009. Mr. Yu is a China certified public accountant.

Mr. Yu would bring to the Board extensive accounting experience as well as management experience through his roles at engine manufacturers.

Courtney C. Shea has served as a director of the Company since July 24, 2025. In addition, she serves as a member of the Audit Committee.

Ms. Shea had an over 30 years’ experience in U.S. public finance in which she served as both a municipal advisor and investment banker working with state and local governments, not for profits and universities, in their issuance of municipal bonds. Ms. Shea served as the Managing Member of Columbia Capital Management, a national municipal advisory firm, from September 2013 until her retirement from the firm in April 2021. Prior to her tenure at Columbia Capital Management, Ms. Shea was an investment banker with several Wall Street firms, including serving as National Head of Public Finance at a division of ABN AMRO for five years. Ms. Shea has served as an independent director and member of Audit, Environmental and Social Responsibility, Finance and Risk Oversight Committees of Assured Guaranty Ltd., a public company listed on the New York Stock Exchange since May 2021. Ms. Shea was an independent director and Audit Committee chair of the Professional Diversity Network from March 2019 until August 2024. Additionally, she serves on several not-for profit boards, including the Joffrey Ballet and the Milken Institute Center for Financial Markets Public Finance Advisory Council. Ms. Shea was a founding member of Women in Public Finance, a women’s professional organization founded in 1996, and has been a Certified Director by the National Association of Corporate Directors. Ms. Shea holds a Cybersecurity Certification from the Private Directors Association. Ms. Shea is an Illinois licensed attorney.

Ms. Shea has a Bachelor’s degree in Economics from University of Notre Dame, a Juris Doctor degree from Loyola University Law School, and a Masters of Business Administration degree from University of Chicago Graduate School of Business.

Ms. Shea will bring to the Board skills and experience in finance, auditing and risk management.

Mr. Xuesen Yang currently serves as Vice President of Weichai Holding Group Co., Ltd., and has served as Chairman and Chief Operating Officer of Weichai America Corp. since  October 1, 2025. He has over 20 years of extensive executive-level experience within the Weichai organization, with responsibilities for overseeing investment strategy, planning, and program management, including managing fixed asset investments.

Mr. Yang holds a Master’s degree in Technical Economy and Management from Tianjin University (2005) and a Bachelor’s degree in Business Administration from Hebei Institute of Architectural Science and Technology (2003). Mr. Yang serves on the Board as a Weichai designee.

Mr. Zhao Jin currently serves as Vice General Manager of Weichai Holding Group Co., Ltd., a multi-field and multi-industry international group. He brings extensive experience in international business operations and cross-regional management, having held various leadership positions across multiple Weichai subsidiaries and international affiliates. Mr. Jin’s current and recent leadership roles include Chairman of Ferretti International Holding S.P.A., Director of Ferretti S.P.A., Chairman of Supervisory Board of Société Internationale des Moteurs Baudouin, and Chairman of Weichai Middle East FZE. He previously served as General Manager and Chairman of Shandong Weichai Import and Export Co., Ltd., and held senior executive positions at Weichai Power Equipment Co., Ltd., including Chairman and General Manager roles. Mr. Jin has specialized expertise in international sales, overseas marketing of power equipment, and cross-regional business management.

Mr. Jin earned his Bachelor’s degree in Thermal Energy & Power Engineering from Harbin Institute of Technology in 2005. Mr. Jin serves on the Board as a Weichai designee.