Cat. H-22-1.5-Collagen: 22 mm diameter, # 1.5 thickness, 45 pieces of CE certified crystal clear German glass coverslips with rat tail type I collagen coating on both sides for cell culture and confocal fluorescence microscopy, sealed 15 pieces per bag x 3 = 45, sterilized, ready to use. Other considerations: GG-22-1.5-collagen, H-22-collagen, GG-22-collagen.