These 3 x1" CapitolBrand® microscope slides are frosted on one end and allow marking with a pen or pencil for ease of identification. They are made from water-white borosilicate glass to maximize clarity. Edges are ground smooth to be free of sharp surfaces. Ready to use without further treatment or washing. Slides are 1mm thick. 72/Box. CapitolBrand® #: M3504-1F.