This is a simple belt tensioner that I made to replace my spring tensioners it is a single print and uses a cable tie to pull the belt shorter. It shortens it by about 11mm ( almost 1/2 inch) and takes up about the same space as the spring tensioners I was using the belt goes through the large opening put a cable tie through the slot and tighten it pulls the belt into the grove till tight. belt notches facing outward,