Product Description: Durable Chain Tensioner Roller for Motorized Bicycles Optimize your motorized bicycle's performance with our high-quality Chain Tensioner Rollers. Designed for specific engine models, these rollers ensure smooth and efficient operation for a superior riding experience. Applicable Model: These pulley tensioner rollers are specially designed for 49cc, 66cc, and 80cc engine motorized bicycles. Please confirm your bike's compatibility before purchasing to ensure a perfect fit and optimal performance. Function: Our pulley tensioner rollers are engineered to reduce pressure on the chain, maintaining consistent tension throughout your ride. This feature enhances the overall smoothness of your biking experience, providing you with a more enjoyable journey. Sturdy Build: Constructed from high-strength materials, these rollers are resistant to deformation and cracking. Their robust construction ensures long-lasting durability, even under demanding conditions, providing you with reliable performance over time. Direct Replacement: Designed for easy installation, these pulley tensioner rollers serve as a direct replacement for damaged original parts. Enjoy a quick and hassle-free upgrade that restores your bike's functionality and performance. Package Includes: Each package contains a pair of pulley tensioners with a 9mm installation inner diameter, making them a necessary accessory for your motorized bicycle. Ensure your bike is equipped with the right components for optimal operation. Enhance your motorized bicycle with our durable Chain Tensioner Rollers, offering reliable tension management and smooth riding. Experience improved performance and durability with this essential bike accessory.