Length adjuster for Tibetan meditation belt

Tibetan meditaiotn belts made in Nepal (https://tibetanhandloom.com/detail-page?pid=7198) are affordable and easy to get online. However they come in one length (208 cm). This belt adjuster style enables shortening the length of the belt (to fit various sizes or for varying posture uses) without the need for sewing or needle pins.
Its designed for 100mm wide belts. The belt is inserted directly in a double ply fashion, so no cutting or sewing is needed.