The Haag-Streit Applanation Tonometer BC 900 can be used in combination with any BC or BD slit lamp. Haag-Streit production assures reliable performance and longevity along with the best reproducibility and accuracy, with average deviation not exceeding .5 mm Hg. The BC 900 uses the Goldman Applanation Principle to measure intraocular pressure. Gold standard in IOP measurement Best reproducibility and accuracy In combination with any slit lamp Reliable and durable Reusable and disposable tonometer prisms