M22 replacement o-rings will fit in any 14mm & 15mm versions. From amateurs to contract cleaners, everybody blows out O-rings, the difference is that the Pro's always have a few spare O-Rings in the truck.

Buna Nitril is a common and inexpensive compound used in the O-Rings of all Brass Couplers. This compound will perform acceptably at high temperatures but will deteriorate quickly and should only be used in cold water applications.