Seca S20 (Stethoscope with a standard membrane side and a bell side as well as a two channel tube) Digital Display Measurment accuracy: Pressure ±3 mmHG Measurment accuracy: Pressure ±3 mmHG Pulse ±5% On the outside a highly polished and non porous chrome plated surface ensures perfect hygiene and a premium finish The child friendly design on the membrane side of the double sided chest piece makes it easier to make contact with smaller patients without causing fear and is suited for the auscultation of children to infants The convex prestressed membrane guarantees perfect skin contact for perfect resonance and sound transmission