Standard Features: Multiple doctor configurations Live waveform display Consistent, operator independent measurements Proprietary pattern recognition algorithm eliminates corneal compression readings Intuitive, user friendly interface SRK/T, SRK II, Holladay, Binkhorst II formulas Stores programmable data for eight IOLs Internal graphics printer Solid tip, 3mm diameter probe Audible guidance to axial alignment Automatic and manual gain control modes Automatic measurements - no foot switch Can be upgraded to add Pachymetry An upgrade of a water immersion option, using the Prager Shell is available on all Model DGH 5000es and DGH 5100es.