This tension roller guides and tensions the drive belt for the air compressor on the host tractor. It maintains proper belt wrap on the compressor pulley so that the compressor receives full mechanical drive without slip. A worn or seized roller bearing causes belt squeal, reduced compressor output, and accelerated belt wear. The roller is manufactured to match the original assembly's bore and outer diameter, ensuring the belt tracks correctly on the pulley face without requiring shimming or adapter sleeves. On installation, verify the belt alignment across the roller and compressor pulley before tensioning to the specified deflection.