The Rissy Universal Reducer and Plug is a must have for any installer. Designed to fit typical 4 inch cast in plastic seals like the Miniboot, it will reduce the seal to a smaller diameter or plug it altogether.  

 Universal Reducer and Plug URP-432

The URP is shown here plugging a Miniboot Pipe Seal. Great for changes or corrections.

The URP will reduce to 3 inch SDR and SCH40 pipe.

 And reduce to 2 inch pipe. Great for pump chamber installs.