AIR SUSPENSION SEAT - 12 VOLT ONLY. NARROW BASE AIR SUSPENSION. (SHOWN WITH OPTIONAL HEADREST $201.30 AND ARMRESTS $206.80 EACH). Maximum comfort for medium-sized and heavy tractors. The MAXIMO XXL's low-frequency suspension is designed to compensate for vibrations in heavy tractors and tractors with axial or cabin suspension. It works by absorbing most vertical vibrations and jolts, thus preventing the buildup of violent rocking.