The AT 020 and AT 030 Applanation Tonometers from Carl Zeiss allow precise measurement of intraocular pressure. Depending on your preference, you can attach an upright tonometer with an working position over the slit lamp swivel joint or mount a suspended tonometer on the stereomicroscope.
They were designed on the principle introduced by Professor Goldmann. This principle represents the gold standard in tonometry. Adapters allow the tonometers to be mounted to different slit lamps. Naturally, even with a mounted applanation tonometer, you still have the possibility for later slit lamp extensions.