This time, we attached a Gentex PM HALO/HAHO Oxygen Mask to a Classic Pro-Tec helmet. The setup looks really great. Pro-Tec skate helmet was developed in 1970s. It was widely adopted by the US military as a bump helmet. Many US SOF operators modified it for HALO parachute jumps. The modified Pro-Tec helmet has bayonet lugs to accept oxygen mask. The Gentex PM HALO/HAHO Oxygen Mask is one of the latest oxygen masks designed for High Altitude – Low Opening (HALO) and High Altitude – High Opening (HAHO) jumps. It offers unsurpassed life support and performance benefits for airborne operations.