Spirit Level Information How to Read a Spirit Level How to Use a Spirit Level How to Check a Spirit Level for Accuracy How to Level a Scope with a Bubble Level View all spirit and bubble levels from Johnson Level . A Spirit Level is a tool used to indicate how parallel ( level ) or perpendicular (plumb) a surface is relative to the earth. A spirit level gets its name from the mineral spirit solution inside the levels. Typically, the vials in a spirit level are a yellowish-green color with ... About this item Compact Size: The BOSCH Spirit Level 12cm is designed for small-scale projects, offering a portable and convenient tool for precise leveling in tight spaces. High-Precision Bubble: Equipped with a high-precision vial, the spirit level provides accurate readings for horizontal surfaces. The humble spirit level — and its highly sophisticated cousin, the precision level — are truly unsung heroes. Whether you’re a seasoned engineer, a machine tool expert, or just a curious enthusiast, never underestimate the importance of correct leveling. Spirit levels are instruments for identifying whether a surface is vertical, or perpendicular to the ground, or horizontal, or parallel to the ground.