About this item LIGHTWEIGHT & DURABLE The water bottle holder is made of high-quality aluminum which means water bottle holder only weights 1.3 ounces(37g). With no welded portions, the bottle holder is very flexible and will not break easily. UNIVERSAL DESIGN & SECURE HOLD The bicycle bottle cages can firmly hold the bottle on the mountain bike. There is no need to worry about it falling during your ride. The smooth surfaces of the bicycle bottle holder will keep your bike secure. ADJUSTABLE BOTTLE CAGES The bicycle cup holder can be adjusted to fit bottles from 2.7in-3in in diameter. This water bottle cage brackets hold a bottle with a 3in diameter perfectly. Fit most standard sized water bottles. EASY TO INSTALL There are 4 standard size screws come with the package for bike water bottle cage mounting. The designed mounting hole allows for fine-tuning of position on the frame. An Allen wrench is provided for installation and you may need cut through metal a bit to screw the bolts. It will be very tied eventually.