You will need to wait again to get the new Strike Industries Viper Modular Fixed Stock. When they released it at their online store, it immediately went out of stock. Until an airsoft version is made, this probably would only fit Gas Blowback  ARs. Here is a video to show you more about it... "The Strike Industries Modular Fixed Stock combines the versatility and adjustability of a collapsible stock with the strength, ergonomics, and solid fit of a fixed stock. The SI MFS uses a standard carbine length receiver extension and is adjusted using the included shim set to change length of pull. "