The gun has a sprung trigger mechanism and flow adjuster knob to ensure fine control over the foam output, and to provide a clean, even bead for the accurate installation of the foam which helps to reduce waste. The barrel is hermetically sealed once the trigger has been released to prevent the hardening of the foam when left in the gun. The Foam Gun has non-stick coated needle and canisters fitting valve and a stainless steel barrel to help make cleaning the gun easier. It is supplied complete with two types of additional plastic extension barrels to give better access when used in certain applications. Supplied with: 2 x Long plastic extension barrels. 2 x Short plastic narrow access barrels.