14 20 00 Elevators
14 21 00 Electric Traction Elevators
14 21 13 Electric Traction Freight Elevators 14 21 23 Electric Traction Passenger Elevators 14 21 23.13 Machine Room Electric Traction Passenger Elevators 14 21 23.16 Machine Room-Less Electric Traction Passenger Elevators 14 21 33 Electric Traction Residential Elevators 14 21 43 Electric Traction Service Elevators