Easy installation Fits MB165 & MB200 Keep a spare Chain tensioner spring for the Baja Motorsports Mini Bike MB165 & MB200 This is a little mini bike part that will render your bike useless if broken Chain tensioner spring for the Baja Motorsports Mini Bike MB165 & MB200. This is a little mini bike part that will render your bike useless if broken. Pick up a few extra to keep you riding. Baja Motorsports has used several spring designs for their mini bike chain tensioners. This is the “small spring” version.,Inside Diameter: 5/8″,Ask a question about this product: Ask Question Thank you for the question!Questions are usually answered within 1-2 business days.