Collars H 250-400 are used to connect the membranes with any through pipes. They have a large flange to ensure an excellent incorporation with prefabricated membranes. The H 250 models can be easily cut following the guidelines, increasing the outlet diameter to 20, 25 or 30 mm for Ø 18 and to 30, 35 or 40 mm for Ø 28.