The replacement chain tensioner is only for the Razor E300, versions 36 and up. It is unique to that scooter.
This item is sometimes out of stock from Razor Scooters USA for an extended period of time. Because of this, we try to order it from Razor in large quantities, however the best plan is to order one more than you need and try to keep the extra tensioner as a spare.
If our inventory is out of stock and all you really need is the spring, please see the item page for the chain tensioner spring at the link below:
Razor Chain Tensioner Spring (Multiple Choices)Note:
Scooter versions can be determined by locating your bar code ID on the bottom of the scooter/deck. The 7th and 8th digit in the series will tell you the version of your product: 01=version 1; 02=version 2; 09=version 9, and so on.