Flair-It PEX and polybutylene fittings meet IAPMO, NSF, and CSA specifications and are ideal for professional installation or do it yourself plumbing repair. Flair-It PEX and polybutylene fittings do not require any special tools. Installation is easy – cut the tubing square, slide the nut along the tubing, rock the fitting all the way into the tubing, slide the nut back onto the fitting and tighten it as far as it will go. Flair-It fittings have been the standard do-it-yourself polybutylene repair solution for twenty years. When using Flair-It fittings with 3/4” polybutylene, use part # 06790 PB insert.