Homesure Mini Level Portable Increased Flexibility Narrow Magnetic Two Way Easy Grabbing Keychain

Description

A confirmation method of precision 1.confirm if the air bubble is within the indication line. 2.At the same place, put the level upside,reconfirm if the air bubble is still within the indication line.[If the movement of the air bubble is within 0.8 mm] [0.0315], it meets the precision standard. Perform before measurement  1.confirm the precision 2.confirm if the measuring aspect and magnet part have any rubbish etc.