These are 40mm round blank high quality glass microscope slides. Slides are optically clear and are used in the FCS2 and FCS3 Chambers to create the optical cavity. See number 7 in the first picture of the FCS2 chamber or number 3 in bottom picture, FCS3 chamber. Packages of coverslips are available in quantities of 200, 500, and 1,000 packs.
40mm Coverslips (200, 500, or 1000 quantity)