Unique Sensor detects the amount of pressure on the leash. Intelligent activator turns on when the dog pulls extra hard on the leash, but doesn't turn on during normal activity. Patented motivational process adjusts the amount of correction to match the dog's abnormal pull on the leash. Three user-selectable levels of correction. Water-tight, heavy-impact, plastic housing. 32 inches long, one inch wide nylon collar strap with metal buckle included. 3-volt lithium battery (thousands of activations) Non-rechargeable user replaceable battery. Weight: 8 oz. (housing, collar strap and battery). 7 minute "Electronic dog training leash" demonstration video CD. Made in the U.S.A.