This plumbing pipe coupling is lead free and made of durable, corrosion resistant brass. It's used to connect 2 lengths of pipe either of the same size or from 1 size to reduce to another size. Couplings are best used in low to medium pressure installs and can be used for water, gas and oil. Easy to install for both the PRO and DIYer. Complies with NSF 61 and 372 and is registered in Mass.