The safety can opener is a very good tool. It opens cans without a sharp edge in the can lid to cut. It is only the double seam pressed on the lid of the can (do not cut, as described in part). The cover can then sit on again to protect the contents of the can, if you use up those not directly.
We have also the predecessor of the can opener for nearly 20 years and now runs even perfect. Definitely recommended!
