I think Dalton hit it right on the head.... copper boppers are easy to make, cheap and work very well. For very little investment you can make various sizes and if you wear one out, pennies to replace the cap. If you live in an area like I live in with no wildlife sporting large antlers, purchasing antler boppers can get expensive in a hurry. I can go down to any hardware store and get all the copper caps I want. ABO is cool, but copper is cheap.