Pneumatic Stroke Completion Sensors
  Stroke Completion Sensors (SCS) mount directly on cylinder ports to provide an air signal when rod motion stops...even when the full stroke length is not used. Stroke completion sensors automatically adjust to variable strokes, replacing limit and reed switches in clamping, holding and sequencing tasks.

Sensors work by comparing supply pressurre to exhaust pressure on both sides of the piston. Once the pressure drops on the exhaust side of the cylinder, the sensor will emit an air signal. Stroke completion sensors are not recommended for cylinder “inching” operations with pressure held valves.