The arm cuff portion of the assembly is “U” shaped and fits your arm more comfortably than the plastic Minelab “V” shaped arm cuff. It’s extremely durable, lightweight, and very comfortable. You'll never have to worry about breaking this one in the field or need to carry around a spare plastic back-up arm cuff. While stainless may seem like the ideal solution, but the weight of the cuff was a major consideration. Aluminum is 1/3 of the weight of stainless steel for the same thickness of material but still very strong. In testing, to reduce the weight of the SS cuff, we had to reduce the gauge of stainless used. The thin SS resulted in a cuff that flexed during the lateral sweeping of the detector. However, by using aluminum we were able to have the needed rigidity and while keeping the cuff lightweight. Although rigid, because they are made from aluminum, the cup width can be adjusted to the specific user. Spread if it too narrow or squeezed together as needed for the ideal fit. The cuff and base are completely welded along each side of the cuff. The base of the cuff conforms to the shape of the battery housing. The base covers the mounting screw slide slot over the full range of cuff adjustment to form a shield from dirt or rain from getting into the detector’s battery housing through the adjustment slot. The cuff will not turn or rotate on the mounting screw because of the contoured shape of the base.