Double net ruling, includes 2 haemocytometer glass covers, with LOT number on the packaging, labelled with: usable until, CE pursuant to IVD 98/79 EC. The ruling shows 9 large squares of 1 mm² each. These are used for counting leucocytes. Each large square is subdivided by double lines into 16 group squares with 0.2 mm sides. The group squares correspond in size to the Neubauer counting chamber, but have no further subdivisions. They are used for counting thrombocytes and erythrocytes. The double lines form mini squares with an area of 0.0025 mm2.