Infant Dual Stethoscope, Sklar. 30 in., Stainless Steel / PVC, Black. Sklar's Newborn Stethoscope features a traditional bell/diaphragm design and is sized and acoustically tailored for newborn infants. The bell on this instrument measures 1-3/16 inches and the diaphragm measures 1-3/16 inches. The overall length of this product is 30 inches and the PVC tubing is light black.