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. The H 400 models, on the other hand, are available in four different diameters and the tang is slightly tapered to facilitate installation. The elastic material with which they are produced ensures long-term watertightness. They have excellent resistance to deterioration caused by the sun, ozone and other atmospheric or chemical agents normally present. They are fully compatible with prefabricated PVC synthetic membranes. Thorough cleaning of the collar and the synthetic felt is recommended near the connection area to the collar.