Heavy duty 26x589mm profile professional quality extruded aluminium spirit levels. Crush proof, durable tubular vials with high transparency for easy reading. Highly resistant to ultraviolet light and fluctuations in temperature the bubble is also not affected by static electricity. Shock absorbent end protectors and temperature proof vial mountings. Measurement accuracy of 0.75mm/m upside down and 0.5mm/min normal position.