The Dogtra Edge RT offers a 1-mile range of low to high stimulation for demanding training situations. It is able to expand into a three dog unit controlled seamlessly with an ergonomic handheld transmitter. This unit features an 8 level selector dial that can be turned up or down without visual confirmation. It has a remote activated multi-mode locator light, non-stimulating vibration (page), 2-hour rapid charge batteries, LCD display screen, and a 1 inch strap. Both the receiver collar and transmitter are waterproof and submersible. Features an interchangeable stim level dial that lets you choose a smooth adjusting rheostat or clicking selector.