specially made for the large microscope slides Large Cover Glass Thickness: #2 (0.19-0.25mm) Made from optical grade borosilicate glass. Made for large microscope slides of 4 x 3" (102 x 76mm) to 7 x 5" (178 x 127mm). Large Cover Glass Thickness: #1 (0.13-0.16mm) and #1.5 (0.16-0.19mm) Made of optical grade borosilicate glass. Made for large microscope slides of 3 x 1-1/2" (75 x 38mm) and 3 x 2" (75.2 x 50.4mm) or larger. Typical Values of Coverglass (39KB PDF) ClariTex Cover Glass for HISTOBOND® + and ClariTex Super Mega Slides This coverglass is sized to match the working area of the HISTOBOND® + Super Mega Slide. Thickness: #1.5, #1Dimensions: 64 x 50mm ClariTex Super Mega Glass Microscope Slides