BMI Robust spirit levels feature an extremely torsion-resistant 4-chamber profile (60 x 26 mm crosscut). Highest accuracy (0.5 mm / m) due to ultrasonically welded vials. Inverted measurement (0.5 mm / m).  BMI spirit levels feature rounded magnification vials which prevent the “double bubble” effect that is found on conventional square vials, which provides the user with increased accuracy.  The domed round vial with magnifying effect provides unsurpassed readability, also for inverted measurement. Two milled measuring surfaces (up to 200 cm) Shock-absorbing rubber endcaps preserve high measuring accuracy.  Available in a range of sizes and with or without hand holes.  Premium quality levels that are made in Germany.