1. Visual Electronic Device for Easier bed leveling: it's a gadget that most too can do without for your FDM printer: get this, keep away from paper, this allows you to not have to update or change firmware to make use of this in most cases, create a nearly perfect leveled buildplate. 2. How to use it: Put the board and cross under the nozzle in the middle of the bed, Move the Z down, progressively smaller steps, until the light just starts to flicker; Disable your steppers, Move to each corner and adjust them until the light just flickers, Repeat the corner adjustments 2 to 4 times until all are set to just flicker without adjustment; Do a Z offset wizard and verify the default, You're done. 3. What it does not do - general 5.7-5.8mm z offset.Does not "preset" your z-offset while leveling your build plate. you will still need to assign the proper z-offset in the printer settings. 4. PERFECTLY LEVEL BED: This tool will give you visual feedback to perfectly adjust the bed level on your 3D printer. 5. Small part, so when tighten the power or replace, please be more patiently to operate it. NOTE: In order to avoid being returned, without batteries, please do not place an order if you mind. Use tutorial: https: //youtu.be/uI_vQWS254U FEATURED DESIGN: more suitable to hold with fingers Notice: You need to bring your own battery model for installation: CR2302 3V button lithium battery. size: 80 x 23mm Material: plastic+metal colour: Black Package Contents: 1 x E-Leveler (Battery not included) Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.