Review on 🚴 Bike Tubeless Presta Valve Stem Kit - Super Light Alloy - Tubeless Valve Stem with Valve Core Remover Tool & Alloy Presta Valve Stem Caps - Available in Various Sizes (Black, 44mm) by Thimothy Purnell

I hate leaving negative reviews, so I'll just state the facts and let you decide. I've been using Presta valves on both road and mountain bikes for about 40 years and have never had a break. When inflating my tire, as I have done hundreds of times before with other Presta valves, the valve body broke right where the smooth machined surface meets the threaded part (see photo). This happened when I was removing the air hose which I always pull straight up and not at an angle so as not to bend the air valve inner seal head. The valve is 2 weeks old and this is my third or fourth time adding air to this new valve. I called my local bike shop and they recommended using Stan's because Stan's uses the best materials that won't break. Stan's Presta valves (2 pack) are $26.50 at your local bike shop, I'm sure you can find them online for a lower price.