Prevents air leaks on suction side of pool pump thread. No teflon tape needed just install on your pool pump and plumb. 2 in. MIP x 2 in. PVC Hi-Temp Union by CMP • 21063-200-000 • CMP Hi-Temp Union 2" inch MIP x 2" inch PVC • CMP Hi-Temp Union • Whisperflo & Intelliflo hi-temp union