MBP, Madison Bicycle Parts, Alloy Presta Tubeless Valve Stems are designed from expert mechanic experience. The base is larger than most stems to accommodate a wide variety of rim designs. Our stems also feature two bases that will end up fitting almost all bicycle rims on the market. The stem, nut, and cap are all made of aluminum. They are tried and tested to be top quality. They are lightweight due to their alloy construction and very sturdy. The stems have removable valve cores for ease of use injecting sealant. (Length Size: 65mm). 1 Year Manufacturer warranty on all MBP parts against defects. Satisfaction Guaranteed.