These are 500pc blank glass microscope slides and 1000pc square coverslips with high quality. The slides and cover slips are pre-cleaned flat and optically clear. The dimensions of the slide are 1 x 3 x 1/8 (25.4x76.2x1.25mm) with ground edges and those of the coverslips are 3/4 x 3/4 x 0.006 (18x18x0.13mm). They are in factory-sealed boxes. Features & Specifications: Quantity: 500 blank slides and 1000 coverslips Dimensions of Slide: 1 x 3 (25.4x76.2mm) Dimensions of Cover Slips: 23/32 x 23/32x0.006 (18x18x0.15mm)