Frame brass.
Tubular bubble vial glass.

Nickel-plated and high-gloss polished. Form B: black anodised.

Bubble levels are used as a type of zero indicator instrument for checking horizontal inclination in e.g. spirit levels, inclinometers, metrology instruments and machine constructions.
The tubular levels can be fastened using the two holes.
- Form A: one sight window
- Form B: three sight windows
- Sensitivity in angular minutes for 2 mm bubble travel
- Green filling

-35 °C up to +55 °C.