The lightweight aluminum valve stems are half the weight of our standard brass valves, weighing only 8g, 9g or 10g per valve respectively for the 35mm, 44mm and 55mm models. Secure round base is compatible with most tubeless rims and a perfect fit for all Stan's BST and BST-R rims. Removable valve core makes adding sealant easy. Fits up to 8mm valve hole.