Wedi Subliner Dry flex collar for 1/2" to 3/4" pipe protrusions. 

Subliner Dry is a waterproof, thin-layer, crack isolating sealing mat is made from highly tear-resistant polyethylene film, which offers optimum connection to tile laying materials thanks to its dual-sided special fleece lamination. The installation over preexisting wall surfaces is smooth and any thinset suitable for the tile or stone finish may be used on top of the Wedi system. The Wedi Subliner Dry is part of the Wedi System which includes Wedi sealing tape, prefabricated corner tape, and plumbing fixture collars as well as bonding flange drains.