It`s simple, but the Carlson`s Choke Tubes Universal Wrench is tough enough to remove or insert chokes quickly. Made to fit 12 ga., 20 ga., 16 ga., 10 ga., and 28 ga. choke systems and, this universal wrench will "wrench" any choke with a slotted end. Formed of heat-treated stainless steel to prevent bending and rust, this wrench is easy to operate, requiring only your index finger and thumb to use it. It`s flat so it fits nicely in a pocket of your hunting jacket or your range bag. Even better, it`s fitted with a key chain, allowing you to keep it on you at all times.