This regulation proposes uniform provisions for the approval of electric powertrain retrofit systems (EPRS) intended for the conversion of vehicles of categories M and N to electric propulsion. It establishes requirements for EPRS design, installation by authorized installers, type approval procedures, application ranges, markings, conformity of production, and modification or extension of approvals. Specific requirements for compliance with applicable UN Regulations are defined, including electromagnetic compatibility, braking, power measurement, rechargeable energy storage systems, and mass and dimension limits. The regulation applies to both pure electric vehicles (EV) and hydrogen fuel cell vehicles (HFCV).