Welch Allyn/Hillrom Professional Adult Stethoscope 222 – High Performance Stainless Steel Acoustic InstrumentWelch Allyn Hillrom Professional Adult Stethoscope 222 High Performance Stainless Steel Acoustic Instrument The Welch Allyn Professional Adult Stethoscope is a lightweight, durable stethoscope designed with versatility in mind. The Professional stethoscope provides medical professionals with a broad range of auscultation capabilities, from the very low pitch (20 100 Hz) of certain heart murmurs to the higher frequencies (100 500 Hz) of aortic and