I have a pair of nearly new adjustable grips for holding items like rifles, shotguns, bows, tools, fishing poles, etc. They have a universal mounting system for an ATV, UTV, truck, boat, etc. They bolt to flat surfaces or clamp to rack pipes from 3/4 to 2 inches. More information available at https://www.kolpin.com/en-us/shop/accessories/gun-transport-carriers/rhino-grips/xlr/rhino-grip-xlr/