●Double protection & warranty: The packaging uses vacuum packaging and bubble bags for double protection to prevent the glass from being damaged during transportation. If you receive damaged goods, please contact us for replacement. ●This is a package of pre-cleaned 50 pieces clear microscope blank slides and 100 pieces 22mmx22mm square glass cover slips ●Dimensions of Slides: 1" x 3" (25.4x76.2mm) with ground edges, Dimensions of Cover Slips: 7/8x7/8x0.006" (22x22x0.15mm) ●Rounded edge design not easy to scratch hands. ●Universal Use: suitable for all monocular binocular trinocular microscopes Material: optical glass