100% brand new aftermarket Boost Pipe Fitting that has never been used. This fitting allows you to fit a boost gauge or any other type of instrument where vacuum or boost pressure is required. Made of high quality aluminum alloy and durable to use. Easy installation,simply drill a 8mm hole in your silicone boost pipe and push the nipple through the hole (from the inside), put on the sealing o-ring, washer and tighten down with the nut. Fit for a 4mm inner diameter pipe.