Recoil spring tester is a simple testing device that helps you quickly measure the compression strength of any Government-length 1911 recoil spring. Lets you easily check if your gun's spring is getting weak, and you can identify the weight of any unmarked springs you may have lying around. No more worries about damaging the gun with a weak spring or accidentally installing a soft spring when you want to shoot +P ammunition. Recoil spring tester is compact enough to take to the range; fits easily in tool box or shooting bag. Mfg: Secure Firearm Products SPECS: Hard polymer with steel components. Instructions included. Measures springs up to 26 lbs. spring weight. 2 AAA batteries which are required, are not included.