Flair-it fittings are constructed of durable polyoxymethylene (pom) and are compatible with pex and pb. the patented design consists of a nut and flared insert and requires no tools. the fittings push against the id and od of the pipe, creating a strong long-term seal. flair-it fittings are available in 3/8 to 3/4 in and are stocked in bulk and barcoded versions. must be ordered in lots of ten. starter kits are also available. valves are directional.