The Milwaukee MX FUEL? Portable Battery Extension allows you to operate any MX FUEL? Equipment while taking all of the weight of the MX FUEL? battery pack out of your hands, delivering lighter tool weight and less fatigue on handheld equipment. The MX FUEL? Portable Battery Extension maintains peak performance, providing the same power you'd expect from any MX FUEL? Equipment. Fully compatible with all MX FUEL? batteries, this solution allows you to benefit from the most run-time by leveraging our most capable battery packs without compromising on weight and ergonomics. The 8' tether adapter gives you the flexibility to operate hand-held equipment from the ground, a lift, a ladder, or scaffolding. The backpack harness with adjustable straps and carrying handle provides easy transport. Easily remove the backpack harness as needed for use in stationary applications. Its durable construction enables use in the toughest jobsite conditions.