Machine description: 24 IN. DBLE GROUSER PADS W/MUD-S, 3PT SYS-DUAL ROLLER & INDEPENDEN, 4 WAY SEAT ISOLATOR, 5 ABOVE DOOR HID WORK LIGHTS, 501HD 23' BOOM, 934CC ROLLER MOTORS FOR HIGHER T, AM/FN/CD/XM SATELLITE RADIO PCK... more info about the Caterpillar 501HD.