The Zenllihome Rear Shock Replacement is a critical component in your bike's suspension system. This set, model 291R/260, uses a 30mm inner diameter, providing better performance and control on your rides. The SWI200 high-strength steel construction ensures durability, even for heavy-duty bikes that need a 350-650 lbs rate. The 650lbs rate accommodates riders from 250 to 650 lbs, so everyone can benefit from this upgraded shock. With a smooth, comfortable ride, you'll enjoy every mile on your bike.