Article- How to use a spirit level: https://www.johnsonlevel.com/News/SpiritLevelInformation
Video-How to use a spirit level: https://youtu.be/kVsSswu6g7o
Article- How to use a spirit level: https://www.johnsonlevel.com/News/SpiritLevelInformation
Video-How to use a spirit level: https://youtu.be/kVsSswu6g7o