These plastic push-in couplings are compatible with CPC couplings of the series HFC12 / HFC35 or LinkTech couplings of the series 60PP / 60PS. They are coupled by pushing the plug in the sleeve until a "click" is heard. Pushing on the ergonomic plastic unlocking button, which is protected against accidental activation, releases the plug again. It is possible to combine coupling plugs and coupling sockets with and without a shut-off valve and different materials (PP and polysulphone) as desired. The shut-off valve prevents the medium from spilling out when uncoupled.