Amplifies sounds up to 30 times louder than an acoustic scope! The control filter switch on stethoscope head allows user to concentrate on heart or breath sound frequencies within a specific range. Volume is also controlled on stethoscope head. The volume remains at the same volume setting each time the stethoscope is powered on. There are 64 possible volume positions with maximum output of 125 dB, undistorted. Automatic timer powers off stethoscope to conserve the battery. USB-style side output jack allows headphones for a second user to be connected or for connecting to a PC for recording purposes. The stainless steel diaphragm produces 50% greater sound sensitivity, a more comfortable feel, and allows listener to use the split-finger technique. Also includes accessory pack with pediatric diaphragm, plastic adult diaphragm, pediatric and infant bells, and ear tips. Requires one "AAA" battery (not included). One-year parts and labor warranty. Allow extra delivery time.