These incredible Glyde sticks make loading and unloading you boat a breeze. They screw down to the top of the trailer bunks (special screws included) and it's like putting ball bearings under your boat. Don't struggle these slicks reduce the load on the winch and you! Easy to install with a battery powered screw gun at the boat ramp. Available in 2 styles. Heavy duty for boats over 1000lbs and a Light duty version for small and lightweight boats. Once you use them, you will never trailer another boat without it.