2 oz. and packed with features not found on any other radio collar. An auto-flashing LED tells you that the collar is fully operational.PART OF OUR EXCLUSIVE PAWS SYSTEM - PAWS (Pet Activated Wireless System), is an exclusive feature of High Tech Pet and includes:Ultrasonic Line: Designed around our MS-4 and MS-5 Ultrasonic Collars, which power ALL Power Pet Doors, Sound Barrier Indoor Containment, and Yard Barrier Outdoor Containment.