RK 420Mru U-Ring Chain The 420Mru U-Ring Chain, tailored for Honda Monkey and Grom, features RK's exclusive Ultra Thin Seal U-Rings that halve seal thickness to lighten the chain and quadruple lifespan over non-sealed variants. Its efficiency in minimizing adjustment intervals means more time riding, less in maintenance. Features: RK's exclusive Ultra Thin Seal U-Ring design Seal thickness is less than 50 of the most common O-ring seal Lightweight for small displacement applications Includes clip type master link Specifications: Tensile Strength: 4,540 lbs Max CC Rating: 150cc street / 150cc off-road Max Horsepower: 25 Weight: 1.74 lbs per 100 links