Designed by Zak Tool, Inc., the ZT15-SW Tactical Extension Tool converts the Smith & Wesson issue key into a large grip handcuff key with extended reach and full swiveling capability. A specially designed end cap and security pin lock the key in position to prevent loss. If an officer's key breaks, it is easy to install another one. Lifetime Guarantee. The ZT15-SW Extension Tool is not officially endorsed by Smith & Wesson.