Our microscope cover glasses are precleaned and made from clear glass. They are individually inspected and free from moisture, dirty. All of them are flat, uniform. Standard Thickness: 0.13 - 0.17mm or 0.19 - 0.23mm Square sizes, rectangular sizes and circular cover glasses are packed 100 slides in one plastic box and white moistureproof paper wrapped. Each 10 plastic boxes in a paper box out closely vacuumed aluminium or plastic bag. And we also supply other packings for your special requests. product offered by Ningbo Smart Innovation Co., Ltd.