Glass Cover Slip, box of 100, 25mm diameter. High optical quality No.1 (0.13 – 0.16 mm, unless different thickness is specified), glass coverslips. Cover glasses for high performance microscopes, made of chemically resistant borosilicate glass of the first hydrolytic class with precision thickness No. 1.5 (0.170 mm ± 0.005 mm), suitable for in-vitro diagnostic applications.