A&A Manufacturing Gould Valve Complete Repair Kit || 521172 Gamma 4 Venturi The upper middle body is

The upper middle body is the main housing unit for a few different parts that all work together to create the turning power for these suction cleaners

Hayward Poolvergnuegen 4-Wheel Rear Skirt Kit (4-Pack)(White)

this makes it easy to locate and remove or replace if needed

Compatible with Pentair In-Floor systems

This clears out any build-up of deposits which should return the power to the cleaner allowing it to operate correctly

A&A Manufacturing Gould Valve Complete Repair Kit || 521172 Gamma 4 Venturi The upper middle body isA&A Manufacturing Gould Valve Complete Repair Kit 521172 Kit includes: 5 Pistons Gears Glass Actuator Balls 1 Center Pin 3 Shims