Amplifies up to 16x (24db) over traditional acoustic scopes. Patented piezopolymer film contact microphone provides wider frequency response than acoustic mikes used in competing models. Three frequency modes: Bell (15-200Hz) for cardiac sounds, Diaphragm (100-500Hz) for lung sounds, and Extended Range (15-1000Hz). 8 level volume control. Holds last mode and volume setting for convenience. Auto shut-off after 3 minutes extends battery life. Battery warning LED signals when replacement needed. Binaurals fixed at 15° angle for snug aural fit. Specially constructed Adsoft PVC eartips for the ultimate in wearing comfort and acoustic seal. Lightweight and compact- weighs 6 oz, measures just 28". Uses "AAA" battery (included). Made in Korea. 2 Year Warranty.