NUKIUniversal Cylinder - Lock Cylinder for NUKI Smart Lock, Highest Security Class SKG***, Emergency and Danger Function, Set Including 5 Keys, Accessories for Electronic Door Lock, Silver

I installed such a cylinder in the door and used it for only half a year. The door opened/closed 2-10 times a day. Not very often. After half a year, the cylinder stopped opening and blocked the closed door. There was no way to open the door either from the inside or the outside. I had to call specialists and drill out the cylinder. Now I'm afraid to buy the same one again. It looks like the cylinder itself is flimsy and unreliable. I really like the smart lock. But I don’t want to drill out the lock again in the next six months.