The Haag-Streit Applanation Tonometer R 900 measures intraocular pressure with high accuracy, producing an average deviation in any examination of less than .5 mm Hg. Repeated measurements do not result in a massaging effect, so patients' occular pressure is not reduced. The R 900 comes with 2 prisms and has no standardization or calibration difficulties. It can be used in combination with any BM slit lamp, and is designed for users who want the tonometer to remain on the slit lamp permanently. Gold standard in IOP measurement Best reproducibility and accuracy In combination with any slit lamp Reliable and durable Reusable and disposable tonometer prisms