This is a US issue 6-point head strap that fits the US M-17, M-40, M-45 and M-50 gas masks.   May fit others with 6-point mounting, but WILL NOT fit the Israeli as masks (5-point) on this website.  Elastic bands and elastic back-of-head net is more comfortable than the original issue of the M-17 and M-40 masks.  Buckles or other hardware IS NOT included.  Never issued and in perfect condition.