A new actuator generates torque in a different way, with a shaped shaft lug that engages the piston to produce gentle starts and stops. The mechanism has run for 20 million operations under load. The standard black unit with a 0.25-in.-diameter shaft provides 90° rotation and has an anodized-aluminum body. A second version features a PET-resin body and stainless-steel shaft riding on a plastic bearing and is intended for corrosive environments. A third type has a stainless-steel body and shaft and a plastic bearing. The units measure 2.00 in. end to end.