Some smart rings can operate without the need of a mobile phone, such as when interacting with back-end systems on the cloud through or performing standalone functions such as activity tracking. They typically do not have a display and operate by contextual relevance, such as by making a payment when near a payment terminal, unlocking an electronic lock when near the lock, or controlling home appliances when making gestures in the home. Some smart rings have physical or capacitive buttons to use as an activation mechanism, such as to initiate a gesture or make a phone call.[1]