Welcome to the new way of opening up sliding chain link gates with these pack of 4 nylon cantilever rollers Wheel size and shaft size: 7" and 1" Designed to fit 4" square post Will fit 2" square gate frame This pack of 4 black cantilever rollers are made from high-quality nylon and have double sealed bearings. Welcome to the new way of opening sliding chain link gates. This pack of 4 black nylon cantilever rollers brings a state-of-the-art way of opening and closing standard sliding gates. With the high-quality nylon acting as the roller, you will see a tremendous improvement to how smoothly your gate opens and closes. Not only will these cantilever rollers make for a smoother gate opening, but will also alleviate the stress on your gate opener. To make sure every project has the right hardware, these cantilever rollers were developed to fit the square chain link instead of the traditional round. These nylon cantilever rollers feature double-sealed bearings for extended life and are designed to fit 4" square post sizes and 2" square gate frames. No grease required!