•Pilot operated piston spool valve with low actuating force. Unactuated, a small quantity of air of approx. 2.5 l/min escapes in the pilot part, •Venting takes place through a drill hole on the base of the valve and therefore, the area within the four feet of the valve may not be covered, •For switching on machines and fixtures of all kinds, especially in pairs as two-hand control. The small switching force of the servo principle ensures fatigue-free work even in continuous operation, •The bracket around the button protects against accidental actuation.