This devious trainer device provides plenty of shock for your trainee. Offers effective training via electro stimulation, vibration, audio tones, and visual cues. There is a corresponding button for each training method on the long-range wireless remote. Works up to 800 feet away. The adjustable rolling buckle supports a padlock (sold separately) for the option to turn this into a locking collar. Fits necks up to 20 in. circumference. Controller requires 9V battery, not included.