AmScope 50pc Pre-Cleaned Blank Ground Edge Glass Microscope Slides and 100pc Pre-Cleaned Square Glass Cover Slips Coverslips This is a package of pre-cleaned 50pc microscope blank slides and 100pc square cover slips. Slide size: 1" x 3" (25.4x76.2mm) Coverslips size: 23/32 x 23/32" (18x18mm), 0.006" (0.15mm) in thickness Material: optical glass