Belt tensioner 20x20 mm
This belt tensioner is a very easy upgrade for your 3D printer. With this upgrade, it is a piece of cake to tighten an axis' belt and keep it tight. This belt tensioner is compatible with 20x20mm aluminum extrusion profiles used for example for the Ender 3's X-axis. This upgrade is so popular, that Creality added it to the Ender 3 V2.
The standard x-axis belt might be too short to work with this upgrade.