The BLTouch is a very precisely tuned auto bed leveling sensor that can quickly level your bed providing a consistent and repeatable result every time you print. It will also help provide mesh leveling for beds that are not perfectly flat (99% of all beds are not “flat”) and is accurate to 0.005mm. Do not be fooled by clones and only buy from reputable sellers. We purchase direct from manufacturer and sell only genuine Antclabs BLTouch devices made in South Korea. Also make sure your genuine BLTouch has a QR code on the PCB. The current version being sold is v3.1.  For more information please reference the BLTouch manual.