This is a three piece belt anchor system featuring simple slide in belt mounting and an independent belt tighter with fine control over belt tightness. It also offers support to the tightener, and mounting slot holes for alignment. Additional hardware required: 1 x M4 or #8-32 Lock Nut 1 x M4 or #8 (3/16" x 7/16") Washer 1 x M4 x 25mm or #8-32 x 1" Bolt The belt tightener shown in the third picture is from a previous revision, it's here to clearly show how the tightener mounts on the belt. To tighten the belt simply turn the bolt clockwise, as the bolt emerges from the end of the belt tightener it will pull the slack out of the belt. The anchor mounting bolt holes are intentionally done with 5 mm of play to allow you to align the anchors directly with the belt pulleys. Print tips: We print these with the teeth that hold the belt built perpendicular to the ground (that is the teeth 'spines' are oriented up-down). This means that the belt bracket tightener should be printed with the right side facing down as shown in the stls (right from the viewers perspective). The belt bracket anchor is printed on the right side also facing down. Please let me know if you have any problems or suggestions to fine tune the design. Have fun!