An extra robust aluminium level with highly transparent and durable unbreakable block vials the horizontal luminous vial magnifies at 43 30 impact absorbing secure end guards sensitivity of 10 mmm and a tolerance in normal position of 05 mmm inverted 05 mmm the vial fluid is a low viscosity coloured oil mixture that gives the bubble the best possible conditions for movement and is resistant to uv light and temperature fluctuations the bubble is also not affected by static electricity as th