Flange designed to be installed on the glass Ocular MaxField® Autoclavable Four Mirror Gonio Lens (O4MAC, O4MAC-1X, O4MAC-LR, O4MAC-1X-LR), and the Ocular Gaasterland Four Mirror Gonio Lens (OG4MG, OG4MG-1X, OG4MG-LR, OG4MG-1X-LR). Flange made of durable medical polymer, will not break during normal handling and use. Eliminates the need to purchase additional lenses with dedicated flanges. Flange cover is easily removed from the lens for cleaning and sterilization. Compatible with most common disinfection and sterilization methods including steam sterilization.