Stabila 106T Extendable Spirit Level is extremely strong double-chamber profile has 2 finger holes with the red coated end being telescopic. The extremely sturdy construction, in conjunction with the strong eccentric clamp, ensures a high level of accuracy when extended to any position. The printed length scale is ideal for setting the extended length with small plates are provided on one side to even out any irregularities. A reliable partner when aligning higher and longer constructions, the light metal rectangular profile has 1 horizontal vial and 2 vertical vials. Measurement Accuracy: in the normal position 0.029 = 0.5 mm/m. When extended in normal position: 0.057 = 1.0 mm/m. For overhead measurements (in closed position): 0.043 = 0.75 mm/m.