Color-Coded Arm Cuff Blood Pressure Monitor with Backlit Hypertension Indicator. Color back-light indicates where reading stands based on WHO. Green normal, yellow pretension, red hypertension. 90 memories x 2 persons. Each measurement is time/date stamped. Automatic measurement of systolic, diastolic & pulse rate. Large 4" display with large numbers. Average for last 3 readings. Automatic power off conserves battery life. Requires 4 AA batteries (not included). Large cuff 9" - 15" (23- 40 cm).