8" Diameter with 4" slits that gives flexibility and access to the to the various styles of shower valve styles. These 10 TGVS Shower Valve Seals are prefabricated seals made of cut out sections of the TRU-GARD® Vapor-shield waterproofing membrane designed to create a complete seal around protrusion of the shower valve through the TRU-GARD® Vapor-shield membrane make the shower waterproofing envelope water tight and leak-proof. Trugard Shower Valve Seals, like the KERDI-SEAL-MV protects moisture-sensitive solid backing panels at the mixing valve. "Make it Leak-proof"... TRUGARD®