The French keys universal spanners, are fully adjusted with no need for you to know the size of the screw, guaranteeing a strong and secure screwing. With the small key you can screw on screws from 9-14 mm and with the other one from 15-22mm. Each time your key grasps on to three points instead of two, making screwing more secure and stable. They do all the work in jobs where a lot of ordinary keys are needed. You can fix valves, bath pipes, gas pipes, and plumbing of all kinds.