This is a wheeled string trimmer belt compatible with many brands. The belt's purpose is to drive the unit, transferring power from the engine to the cutting head. Over time, belts are subject to wear and tear, heat, and humidity. This can make the belt brittle and eventually it will snap. In other instances, belts will stretch after being used for long periods and need to be replaced. Replacing the belt is a simple process. Start with the engine off and the spark plug disconnected. Remove the screw holding the chassis cover in place and then the screws holding the debris shield. With the debris shield out of the way, the belt should be clearly visible. Remove the engine pulley, but make sure to note the pulley's position for replacement. Install the new belt and reassemble the trimmer. This part is a genuine OEM part sourced directly from the manufacturer and sold individually. This belt is compatible with Craftsman, Bolens, Remington, Ryobi, and Yard-Man brands.