Bicycle Chain Tensioner Guide Wheel Derailleur Spring Pulley Adjustable Repairing Adjuster Oval Tooth Plate Protector Part The product is shipped based on the color or size of the main image of the product page. Description: Compatibility: This kind of bicycle chain tensioner is suitable for single-speed folding bikes, it is a good accessory for bike to keep the chain stable and protect the chain from dropping, ensuring your cycling security. Adjustable: This bike chain guide is designed with pulley and spring, convenient or you to adjust the tightness to get a perfect tension capacity, you can order without worries. Easy to install: This kind of folding bike derailleur part is lightweight, you can install it on the chain frame and it will not disturb your riding, not easy to make trouble for you. Wear-resistant: The chain guard protector is made of aluminum alloy material, sturdy and durable, you can use it for a long time because it is not easy to be cracked. Wide use: This anti-drop tensioner can be used with other idler pulleys, regularly, the gear is 11t, but it also suitable for 13t, please make sure the type of your bike before ordering. Specification: Material: aluminum alloy. Color: black red. Size: show as pictures. Note: Due to the light and screen difference, the items color may be slightly different from the pictures. Please allow a slight deviation for the measurement data and make sure you do not mind before ordering. Package Includes: 1 Piece Bike Chain Tensioner.