System for providing a conduit sealingly to a through-opening in a plate-shaped construction element so that at least one pipe and/or cable can extend through the conduit and so that after sealing remaining space in the conduit a completely sealed-off pipe and/or cable penetration through the plate-shaped construction element is obtained, wherein the system is such that it is mechanically mountable, wherein the system is further such that it is mountable from only one side of the plate-shaped construction element, by only one worker.