The transparent Kabuflex® sleeve made of PP has a double control function: On the one hand, it is clear at a glance whether the necessary sealing rings are present and whether they are in the correct position. On the other hand, the insertion depth of the pipe can be checked. This double plug-in sleeve is used for the sand-tight connection of Kabuflex pipes. The connection of Kabuflex with double plug-in sleeve and profile sealing ring WD is watertight up to 0.5 bar on every pipe.