Chucking a level onto something was always a hassle here in the JTA workshop - the these things rocked up, and we keep two around at all times.
Shinwa's large Blue Eye vials are fantastically easy to read, with clear blue liquid and thick white indicator lines. Their high precision allows them read correctly to within 1mm/metre. The horizontal vial is enclosed within a protective cover that can be removed and washed if needed.
The reference edge of the level is machined straight, with a notch along the centreline that allows the level to reference round surfaces. A powerful magnet has been inserted in the base that makes levelling out anything made of steel dead easy - but which we use to store ours within easy reach in the workshop.
The side caps protect the body from bumps and scrapes.
100mm long x 50mm high x 20mm wide.