690*18*30 Drive Belt.
Circumference (when viewed as a circle).: 690
Width.......................................................: 18
Groove Angle...........................................: 30°
This belt is most four stroke chinese scooters using the 139QMB engine(Short Case Version) with 10 inch wheels. The only time there could be a different belt is when you have a scooter with 12 inch wheels then you might need the 788 size belt.
Made in China