This is a Treadmill Doctor Replacement Drive Belt Part Number 1000415055 / 8006063 Used on the Following Models Listed Below. 

Bowflex -
M3 Max Trainer - 100358 
M3 Max Trainer, Single Box - 100580 
M3 MAX TRAINER, SINGLE BOX - 100942 
M5 COLLEGIATE - 100720 
M5 Max Trainer - 100359 
M5 Max Trainer, Single Box - 100702 
M6 MAX TRAINER - 100879 
M6 MAX TRAINER, SINGLE BOX - 100801 
M6 MAX TRAINER, SINGLE BOX - 100881 
M7 MAX TRAINER, SINGLE BOX - 100779 
M8 MAX TRAINER - 100880 
M8 MAX TRAINER, SINGLE BOX - 100802 
M8 MAX TRAINER, SINGLE BOX - 100882 
M9 Max Trainer - 100944 
MAX TOTAL - 100757 
MAX TOTAL - 100916 
MAX TRAINER M3 - 100426 
MAX TRAINER M3 - 100428 
MAX TRAINER M3 - 100491 
MAX TRAINER M5 - 100427 
MAX TRAINER M5 - 100429 
MAX TRAINER M5 - 100492 
MAX TRAINER M5 - 100697 
MAX TRAINER M5 COLLEGIATE - 100719 
MAX TRAINER M5 COLLEGIATE - 100721 
MAX TRAINER M6 - 100755 
Max Trainer M7 - 100469 
MAX TRAINER M7 - 100469-R 
MAX TRAINER M7 - 100615 
MAX TRAINER M7 - 100616 
MAX TRAINER M7 - 100617 
MAX TRAINER M8 - 100756 
MAX TRAINER M8 PERFORMANCE PACK - 100813