Contractors and DIYers, these strut channel trolleys are seriously heavy-duty! Made from solid steel with two bearings each, they're built to last without deteriorating over time. Each trolley has a fixed size spacer that makes the whole assembly more stable and reduces noise during operation. The custom-built bearings even come with covers to prevent the metal balls from falling out - no lubrication needed either! The welded bearing and pin shaft design provides greater stability and safe operation, while the deep groove ball bearings ensure smooth, quiet movement. These work with all 1-5/8 inch wide strut channels and taller profiles too. With a 9/16 inch diameter hole and 1/4 inch thick plates, these are robust enough for serious use. Perfect for garage winch systems, electric lift setups, ceiling trolley systems, or any application where you need smooth rolling action along strut channels. The pack of 10 means you've got plenty for multiple projects or replacements. Installation is straightforward, and once they're in place, you can count on reliable performance project after project. Seriously, if you work with strut channels regularly, these trolleys will make your life so much easier!