Fit for: / Razor MX350 MX400 SX350 ZR350 Dirt Rocket Bike/ Long term driving of dirt bike can cause chain tensioner wear, looseness, detachment, and even damage Therefore, it is necessary to regularly inspect and replace the chain tensioner to ensure driving safety. Feature: 1. Long of life, 2. High of Quality, 3. Easy to install. Package Including : 1 x Chain Tensioner, 2 x Nut Kit, 5 x 25H Master Link. Please check the description to confirm the compatibility before purchase. Fit for: / Razor MX350 MX400 SX350 ZR350 Dirt Rocket Bike/