(Used) 2013 Allison, PTO- Trans Model; 2100RDS PTO Make: Chelsea PTO Model: 489XQAHX-A3XK Part Number: C1-P-551 Serial Number: 42650956 For more information about this item, give us a call. We ship Worldwide! (CRG HEAVY TRUCK PARTS) 929 W PULASKI HWY ELKTON, MD 21921