EM40S - Medium Back Ergonomic,Syncron Tilt, Swivel, Adjustable Arms, Gas Lift
M40 - Medium Back Ergonomic,Locking Tilt, Swivel, Adjustable Arms, Gas Lift
M42 - Medium Back Ergonomic, Locking Tilt, Swivel, Gas Lift
M Series - Adjustable back lumber support
E40 - Medium Back Ergonomic, Infinite Locking Tilt, Swivel, Arms, Gas Lift
M40HR - Medium Back Ergonomic,Headrest, Locking Tilt, Swivel, Adjustable Arms, Gas Lift
M40HR - Medium Back, Headrest 'Tilt Back and Relax'
M Series - Adjustable arms