This precision instrument from Japan has airtight chestpiece machining crucial to sensitivity and professional quality. Mirror finish with ball-bearing flip-over mechanism. Includes two pair of eartips (white plastic, soft rubber mushroom). Blue tubing with exposed binaural spring. The Sensor Ace has the spring on the inside of the "Y" tubing. The difference is entirely cosmetic. Only a few pieces left of these phenomenal stethoscopes manufactured in Japan before they exported manufacturing overseas. Regular pricing was $29.99. When the last pieces have been sold there will never be another stethoscope like this again. It is too expensive to make them!