For truck and trailer owners, these Shimeyao garage door rollers are built tough for commercial use. You get 12 rollers in the pack - perfect for having spares on hand. Each roller has a 7/16-inch diameter stem and 2-3/4-inch length, designed specifically for 1-inch track systems. They're made from heavy-duty steel with protective coating that resists rust, moisture, and road chemicals, so they hold up in all weather conditions. The precision engineering means they fit exactly without wobble or friction, providing smooth, quiet operation even under heavy loads. Ideal for tractor-trailers, box trucks, utility vans, and other commercial vehicles. Installation is tool-free and straightforward, minimizing downtime for your fleet. These rollers withstand extreme wear and high-impact stress, making them perfect for long-haul transport, construction, and fleet operations. By reducing wear on your track system, they actually help extend the life of your entire door setup. A smart investment that cuts down on maintenance costs and unexpected failures.