Extra strong aluminium profile measuring 59x26 mm and weighing 880 g/m. Transparent and durable Crush-proof block vials with temperature-proof vial mountings, highly resistant to ultraviolet light and temperature fluctuations. Horizontal vial with a +30% magnification lens and luminescent reflector. LENGTH 400 mm VIALS Features Tolerance in normal position is ±0.5 mm/m, upside down ±0.5 mm/m.Focus vial with colour markings for easy reading and with a 200 mm radius giving a sensitivity of 10 mm/m.Shock absorbing end protectors with anti-slip function.The liquid in the vial is a low viscosity coloured oil mixture that gives the bubble optimal freedom of movement.The anti-static properties of the liquid means that the bubble is not affected by static electricity.