Achieve a seamless connection with this specialty adapter. This S-Pump Nipple offers a perfect fit that prevents the threat of leaks. It is designed for use with all S-series vacuum pumps and generators. Teflon tape is not recommended for the threads, vacuum is sealed on the duckbill valve’s built-in O-ring. The use of Teflon tape can cause damage to the fitting or the duckbill valve.