extension d 110 mm with CeraDrain collar incl. O-ring. CeraDrain - the ultimate solution for 'thin bed' waterproofing. The polymer concrete collar lies flush with the screed and the steel mesh limits differential movement between the screed and the drain. A glass fibre mat, bonded to the top of the collar acts as reinforcement at the critical point between the screed and the collar. Height adjustable levelling legs (sound absorbing) provide millimetre-accurate adjustment.