The Mopeka Halo is a thermoplastic rubber foot protective ring for standard cylinders. Protects your bottle locker and floor surfaces from wear marks or rust and grime that builds up on cylinders.
Halo also provides the benefit of providing the space and improved wireless range when used with a standard sensor. So pick one up to protect surfaces or in addition to the aluminum spacers that are provided with sensors.
With or without a sensor, the Halo is a nice way of protection for any propane cylinder user.