ZIPP hex key style valve extensions allow easier installation on tires and tubes for use with ZIPP and other Deep and Mid-v style rims. The new style ZIPP extensions are recognizable from older models by black anodization, a laser etched ZIPP logo and a 3mm hex key fitting in the pump head end. Okay, so they aren’t stylish, but they are an aero-wheel must have item. Will fit any presta valve stem. Three sizes, small for rims up to 40mm, medium for rims up to 60mm and large for rims up to 82mm.