Seal Spa Hot Tub Pump Wet End Seal Kit fits Guangdong LX Pumps How to Video LX Series Jet Pump Seal Kit with Silicon and Install Tool Fits WUA LP and Guangdong LX Pump but Not Jacuzzi Premium or Sundance It is 1 39/64" Across the back of the Spring Seal part See our You Tube Video about this Pump "LX Series Guangdong Pump How To Repair The Spa Guy" Ceramic & Rubber part that goes into the impeller is 1 11/32"