Strong craftsmans aluminium levels with highly transparent and durable unbreakable block vials the horozontal luminous vial magnifies to 43 30 impact absorbing and secure end guards sensitivity of 10 mmm and a tolerance in normal position of 05 mmm inverted 075 mmm the vial fluid is a low viscosity coloured oil mixture that gives the bubble the best possible conditions for movement plus it is resistant to uv light and temperature fluctuations the bubble is also not affected by static electri