Abstract: A power tool operable with an exchangeable tool head, and comprising a tool body, and a hydraulic cylinder with a main piston A quick coupling system is arranged at a free end of the tool body and includes an actuation unit and a locking unit movable by the actuation unit between a released position and a locked position to secure the exchangeable head to the tool body. Thee locking unit comprises a first and a second half-ring radially movable between the released position and the locked position. When in the locked position the locking unit is adapted to secure the exchangeable head to the tool body, such that transmission forces can be exchanged between the exchangeable head and the main piston. When in the released position the locking unit is adapted to release any force applied to the exchangeable head to remove the exchangeable head.