To match your belt you will need to know the inner diameter:
To measure your old complete or broken belts follow this easy guide:
once you know the length of your old belt you can find the inner diameter by dividing it by 3.142
eg: 135mm length ÷ 3.142 = 42.96mm, now check for a belt size slightly smaller than 43mm.
0.5mm X 3mm Audio and Video Flat Square Section Belt, Inner Diameter 25mm