Choicemmed Oxywatch Fingertip Pulse Oximeter: * Includes: 2 AAA batteries, carrying case, lanyard, and instruction manual. * Warranty: 2 year warranty * Great for exercise, mountain climbing and aviation * Measuring range for SpO2: 70-99%. Measuring range for pulse rate: 30-235 beats per minute. Pulse bar graph indicates the intensity of the pulse signal. Highly reliable measurements SpO2 accuracy: SpO2 range from 80%--99%, ±2%; from 70%--79%, ±3%; from 69% and lower, no reading available. * Pulse rate accuracy: from 30-235 beats per minute, ±2% or 2 beats per minute. Resolution: for SpO2 - displays each 1%, for pulse rate- displays each beat. * As with all oximeters, for best results, keep hands still while taking a reading. Fingernail polish and acrylic nails interfere with oximeter readings and result in inaccurate readings. * Note: this device is not intended for self diagnosis and does not replace a doctor"s visit.