Stethoscope heart
Specific features.
First . Using Alkaline batteries 1.5 volt AA batteries 2 .
Two . Lifetime battery 5 hours or more.
Three . 3 minutes automatic shutdown when there is no signal.
. 4 RMS speakers about 250 mW.
Five . Displays heart rate between 60 to 240 bpm.
. 6 LCD screen displays heart rhythm . The volume . And the battery .
Seven . Dimensions 45x135x30 mm.
8th . Weighs about 150 grams (including battery) .