Some of the physical activities performed by Bus Maintainers (Chassis) and environmental conditions they experience are: working outdoors in all weather conditions; crawling under and on top of buses; working in confined areas; lifting and carrying heavy parts, tools, and equipment; climbing into and out buses that are suspended on lifts; reaching into dark spaces and making tactile inspections; making visual inspections of equipment, distinguishing colors; reading gauges and prints; reading, interpreting, and applying written or graphic technical repair instructions; responding to sounds from warning bells, horns, and vehicle movement; and wearing required personal protective equipment. This includes, but is not limited to, the vehicle body, structure, interior panels, trim, seating and glazing; axles, suspension, steering and braking components and systems; driveline or propulsion system components, prime movers and auxiliary drive units; HVAC; lighting and electrical systems; microprocessor controllers, Programmable Logic Controllers (PLCs) and multiplex electronic systems; and vehicle energy storage systems and devices.