Custom Truck One Source, Inc. provides specialty equipment rental and sale services to electric utility transmission and distribution, telecommunications, rail, forestry, waste management, and other infrastructure-related industries in the United States and Canada. It operates through three segments: Equipment Rental Solutions (ERS), Truck and Equipment Sales (TES), and Aftermarket Parts and Services (APS). The ERS segment owns new and used specialty equipment, including truck-mounted aerial lifts, cranes, service trucks, dump trucks, trailers, digger derricks, and other machinery and equipment.