I finally found a stethoscope that is comfortable, clear sounding and quality all in one - and it's made here in the USA! While I'm not a professional, I do understand the basics behind using a stethoscope. I bought this on a recomemndation from a doctor friend and his recommendation was spot on. This stethoscope has two different types of sounds that you can hear based on how much pressure is applied to the diaphragm. While the pressure applied to the ear pieces is sufficient to seal off outside sounds, the shape of the ear buds and the pressure level applied to seal them is still comfortable even while using it for a long time. Having used these for four and a half years, I must say they certainly are top of the line - as I've used many others the last few decades. To put it simply, you won't be disappointed in these!