The Stainless Steel Cylinder for CM.706 series comes as a set with a pre-installed brass cylinder head and is a replacement original part manufactured by CYMA themselves. This can be a handy part to have if you use your CM.706 at different sites with different FPS limits, as you can make a second cylinder and swap them out as and when you need (though this does require disassembly). The set includes both the cylinder and the cylinder head.
Can be fitted inside other rifles including AEG gearboxes. The sorbo pad works by absorbing impact from your piston head, please note you should expect an FPS loss so you may have to improve the air seal or fit a slightly larger spring to regain your desired FPS.