OEM treadbelt (running belt)used on Cybex models 450T, 500T, 515T, 520T, 530T, 550T treadmills. With 58" walking surfaces. 

Units with serial numbers LESS than model 500T = X07-07520T9814NN, model 515T =  X07-07515T9514NN, model 520T = X07-07530T9814N, model 530T & 550T = X07-07530T9814NN

NOTE: These treadbelts require lubrication on them.  Failure to apply a new deck surface and coat of lubrication will void the warranty.