The Russian "Kobra" is a hydropneumatic speargun built using the forward latching design employed in the "RPP" pneumatic speargun, among others. The main difference is the extensive use of molded plastic parts in the mid-handle and muzzle components which were previously all-metal items, plus a much larger diameter air tank. I purchased one of these some years ago when they were being sold locally by a guy who was then importing them. The photos which I took at the time were on one of my old computer hard drives and I just found them, so here they are.