Disable Door Handles/Faucets/Valves - This device is made of stainless steel. It is designed to cover and lock door handles and prevent the knob from turning by locking the knob and keyhole. Fits Most Standard Door Knobs/Handwheels - Suitable for round, tulip, and oval door handles, not suitable for lever door handles. Suitable for faucets/tanks with handwheel valves. Application - Can be used on the outside or inside of knobs. Whether you are outside or sleeping at home or in a hotel, you can use this device to lock the external knob for added security. It can also be used to prevent people with dementia from going out. Easy to Install, Carry, and Store: Simply place the device on the door handle, lock it, and you're done. The device is medium in size. Two options are available: without a lock and with a lock. The option without a lock is not included in the package. You need to use your own lock to lock your device. You can also use a carabiner or rope instead of a lock for simple security needs. If you need to choose a lock, a 304 stainless steel waterproof lock is included in the package. Note: The data are all measured manually. Please allow 1-3cm error. Due to differences in light and display, there may be some color differences. Please refer to the actual item received.