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 Peter Montoya

Got the 2020-1s for the Ender 5. Works for both X and Y axis. Obviously you'll need 3 if you do both. High quality and fits in a few minutes, one of the better upgrades for my Ender. Can finally get the belt tension right without a struggle. Edit: Important, make sure you upgrade your belts, the Creality belts are garbage and if you actually put them at the right tension your print quality will definitely degrade. It took me a week of trial and error to finally figure out I was having issues with the Creality belts. Gates belts are expensive and you will need about 3 meters to do the retrofit but it made all of the difference, go figure. You can find belt stops on Thingverse.