Safety Locks similar to Safety Catchers and Safety Brakes are used against failure of lifting members. But in contrast to those they are not suitable to decelerate masses or to dissipate kinetic energy. On the other hand, the rod displacement to build up the holding force is very small, so that this units can be used for a approximitive positioning tasks as well. Furthermore this design principle allows compact solutions even for small rod sizes (smaller than for Safety Catchers). In the field of pneumatic clamping devices the Safety Locks are providing the absolutely highest holding forces in relation to housing dimensions.