Stainless steel Bore-up cylinder set for the weapons range M16 from SHS. The entire cylinder is made from a single piece of metal by CNC. The cylinder head is an integral part ribbed and polished cylinder, so that there can be no leakage of air or mutual misalignment, as with conventional heads with o-rings. Set contains plastic BU piston head with a conical impact and metal nozzle with o-ring length of 21.5 mm. Unbeatable price/performance ratio.