1X Hot Tub Spa 2 1/2" Split Nut Kit for Pump Union Emergency Repair Video How To 3 3/4" Outside Diameter 3 5/16" Inside Diameter We offer gaskets in our store Threaded Part measures about 3 5/8" Across edge to edge See our YouTube video on this product by searching YouTube for "The Spa Guy How To Hot Tub Pump Union Emergency Repair Split Nuts "