Geissele GEI08-153: The Geissele Maritime Bolt Catch is designed with the warfighter in mind and will work with any lower receiver designed to accept a mil-spec M16/M4 Carbine bolt catch. The increased surface area promotes ease of function when locking back the bolt or releasing the bolt after a magazine change. In addition, the extended controls add increased functionality for left-handed shooters who no longer have to break their grip to manipulate the bolt catch. Left-handed shooters can easily reach the controls using the index finger of their left hand, making magazine changes and locking the bolt back much more efficiently. Aggressive checkering covers the surface of the levers giving the Geissele Maritime Bolt Catch a textured surface that enables positive feedback to the shooter\'s hand when used with gloves or at night. Manufactured from properly heat treated 8620 steel and manganese phosphate coated, the Geissele Maritime Bolt Catch is intended to serve as an enhanced mil-spec replacement and assist in giving our warfighters overmatch capability with the M16/M4 carbine platform.