Review on Befenybay 2020 Upgrade: X-Axis Synchronous Belt Tensioner For Creality Ender-3/Ender3 Pro/Ender3 V2/CR-10/CR-10 V2/CR-10 V3/CR-20 Pro –Straighten And Stretch For Enhanced Performance by Josue Zepeda

3 stars. The quality is good and its made fairly well. The problem is the frame bracket itself is not exactly set to fit the 40mm rail. It's just slightly too small and will pinch together when you fully tighten the T slot screw. It ends up pinching the pulley assembly preventing it from being adjusted as needed. I had to preset the pulley tension before I could fully tighten the T-slot screws. I recommend the seller adding some washers or shims to be used to prevent from fully closing. Or remake the bracket all together. Its disappointing because this was easy to install and would have worked nicely. Bottom line this item will be returned.