Part Number 100884-1200BK.  XM-1200 (all versions) Belt Kit, No Blue Gate Rollers, Includes:
 
(2) 100156:  Carriage, Discharge O-ring belt
(1) 100157:  Carriage, Main Feed Belt, Blue, Perforated Vacuum
(2) 100158: Carriage, Rear Urethane Idler Belt
(2) 100159: Carriage, Front Discharge Urethane Belt
(1) 100187: Separator Drive, Timing Belt, 86XL037
(2) 100196: Carriage, Timing Belt, 160XL037
(1) 350450:  Timing Belt, Main Drive 1, 130XL037