The Dyno BMX Stem for old school BMX bikes is a black aluminum stem with a quill design. It has a 22.2mm clamp diameter and is compatible with 21.1mm steerer tube diameter. This lightweight stem weighs 1.5 lbs and comes with the necessary set includes for installation. Perfect for adding a touch of retro style to your classic BMX bike, the Dyno BMX Stem is a durable and reliable component for your cycling needs.