Wedi Board System Lightweight and waterproof backer board system for tub and/or shower surround. Kit includes: - One 36"x60" center drain base - Six 3'x5' building panels (1/2" thick) - One 5' foam curb - Eight 10.5 oz tubes of joint sealant - One 100 piece fastener kit (washers and screws) - One corner putty knife - Two 16"x22" shower niches with removable shelf