Neubauer Improved Haemocytometer Counting Chambers are moulded from a single piece of thermal and shock-resistant glass. Each chamber comes with two cover glasses included. An H-shaped moat forms either one or two counting areas, or plateaus. Each plateau features an etched grid or ruling. The ruled surface is 0.1mm below the cover glass, limiting the volume of 1 Square mm of blood or fluid over a square mm at 0.1cu.mm. Contact of the flat, polished cover glass surfaces with the cover glass supports produces an exact volume of fluid over the counting area.