High-tube® telescoping stock adapters, require the use of rail mounted optics. The High-tube Adapters mimic the geometry of an AR-15 rifle, which means they can accept any buttstock or grip made for the AR-15. This also means the stock elevation is too high to use receiver- or barrel-mounted sighting systems. This is why High-tube adapter kits usually include a Picatinny scope rail, so that an optical sighting system can be mounted on the weapon.
Note that High-tube adapters must be used with rail-mounted optics or back-up sights, or at least some kind of sighting system positioned high on the receiver.

The High-tube Stock adapter system is designed to allow shooters the ability to fit AR style collapsible stocks and pistol grips onto their shotguns. The versatile telescoping stock adapter system can be fitted with a standard AR-15 grip and telescoping stock, which enables tactical operators to instantly adjust the length of pull of the telescoping stock in order to accommodate differences in individual body sizes or use of body armor.

The concept behind the telescoping stock system is simple: the shotgun’s factory stock is replaced by an adapter, to which standard AR-15 grips and telescoping buttstocks can be reliably attached. All of Mesa Tactical’s stock adapters are investment cast aircraft grade aluminum, machined and powder coated black with a tough, chemical resistant finish.