This part is a Kit that features (1) Seal, Seal Tool and Silicon that fit (4) Mount Style Piranha, Thera-Flo, Thera-Max pumps and The Professor's Silly Juice to seal the seal. It is 1 3/8" Across the back of the Spring Seal part that goes onto the Impeller and the Ceramic & Rubber part that goes into the Volute or Wet End Back is 1 1/4". The Hole in both parts is about 5/8".
Note: This Kit fits the (4) Mount style wet end back with a 1 1/4" Hole in it.. There is a similar wet end with a (8) Mount back that uses a different seal and parts kit with an outside measurement of 1 3/8" for those parts click below:
To Install you should put silicone sealant on the back of the Metal part and gently push it into place. Also the rubber part can use a light coat of silicon to slide it into place in the impeller.
