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 brand new in factory-sealed boxes. Their retail value is $150. 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)