Our Lightweight Nurses Stethoscope (660) combines lightweight comfort, sensitive acoustics, and handsome styling, with truly affordable pricing. Features (660): Lightweight aluminum chestpiece construction. Non-chill diaphragm rim for patient comfort. Proprietary diaphragm enhances acoustic response by 50% over traditional designs. Adjustable chrome plated brass binaurals with PVC eartips. Flexible 22" PVC tubing. Spare pair of black mushroom eartips included. Inspected and packaged in the U.S.A. One year warranty. Non-chill diaphragm only nurse style chestpiece (1 3/4"diameter). Ideally suited for blood pressure measurement. Weighs just 3 oz. Overall 31". Burgundy color. Dualhead (670) Features: Combination diaphragm/bell chestpiece for wide frequency response. Diaphragm diameter 1 3/4", bell diameter 3/4". Non-chill bell ring and diaphragm for patient comfort. Weighs 4 oz. Burgundy color.