Use Stan's Tubeless Valve Stems when you're converting standard rims to tubeless via the taping method. These also have a removable core for easier
Stans No Tubes Universal 35mm & 44mm Mountain Bike Valve Stem
Stans NoTubes Alloy Tubeless Valve Stems [AS0157]
Vittoria Tubeless Multiway Valve Stems
Tubeless Presta Valve - Light Bicycle
THE TEN BEST TUBELESS TIRE VALVE STEMS - AN UNDERRATED UPGRADE
Industry Nine No-Clog Aluminum Tubeless Valve Stems - Components
Profile Design Tubeless Valve Stem Presta - 50mm - St Kilda Cycles
, Compatible with straight valve hole Hugo 52 rims and designed to fit 7.5 - 8.5mm valve holes. Sold as a pair., Identifying your Hugo rim and
Stan's No Tubes Tubeless Valve Stems Schrader Valve - 32mm | Bicycle Tubeless Technology
DT Swiss Brass Tubeless Valve Stems - Cambria Bike
Stans NoTubes Stans Tubeless Valve (pair) - 18 Bikes Ltd
Universal Cycles -- Cush Core Tubeless Valve Stems