KOWA applanation tonometer HA-2 Reads intraocular pressure irrespective of the patient's position - namely any patient sitting in a chair, reclining in a chair or in bed, and also of baby patients. Features Type: Applanation Measurment Range: 0 to 60 mm Hg Alignment: Manual Portability/Weight: handheld/battery operated 0.53 lbs. Options: Optional 3x long eye relief for presbyopic users Additional Features: Handheld and battery operated (2 AA batteries) Built-in illumination permits use regardless of room light. Direct reading of dial requires on conversion table. Adjustable built in head rest steadies the tonometer during measurements. Warranty: One Year Parts & Labor Specification Type: Hand-held applanation tonometer Applanation Prism: Doubling prism (option) Scale Range: 0 ~ 60mm Hg (1mmHg division) Illumination: a) ON / OFF b) Bulb c) Battery used Interlock with thumb wheel Lens Bulb: 2.5V, 0.25A 1.5V, 2 pcs Eyepiece Magnification: 6x Head Rest: Movable Length: 290 mm Weight: 240 g with AAA Batteries Rechargeable Battery: Welch Allyn Battery 72200 (3.5v)