Oatey 34080 Bottom I.D. 11-1/2-Inch x 11-1/2-Inch Tub Box for Slab Construction Top I.D. 13-Inch x 13-Inch/Depth 6 1/2-Inch Provides a quick, economical and clean method of installing tub waste and drain. Manufactured from semi-flexible, very durable, plastic polymer. Built in cut-out for up to 2"" Schedule 40 drain. Enables installer to form a clean cavity in a concrete slab so a trap can be easily connected to the drain system. Offers protection against tub damage during home construction A semi-flexible, heavy, high-impact Plastic with deep-fluted sidewalls Includes a non-skid foam pad to absorb shock and prevent scratched and dented tub finish Nests for space-saving storage