This specimen counting chamber is only 10 microns deep, which is one tenth the depth of other hemacytometers making it the shallowest of known chambers. This quality chamber is constructed from two pieces of optically flat glass: the first is the chamber, the second is the cover glass, which has a fine grid pattern of 1 mm squares and a center area further subdivided into 0.1 mm squares. Four quartz pins of precise height hold the cover glass to give an exact trapped specimen depth of 10 microns. In a protective wooden box with sliding lid.