Strike's Stock Stop allows you to convert your collapsible stock into a fixed stock. The low profile, lightweight Stock Stop fills in all but one receiver extension hole and ensures that the stock cannot be adjusted to another position. Made out of high strength and abrasion resistant thermoplastic, the stop is sure to stay in place, and out of sight. It is compatible with any aftermarket 6-position buffer tube or Strike's 7-position Advanced Receiver Extensions and requires no modification to the buffer tube. No need to drill and pin your existing stock.