Measures quickly and accurately pulse rate and spo2 blood oxygen saturation of arterial hemoglobin levels User can see Pulse Rat,bar graph in this LED display Light and compact, you only need to put your finger in the fingertip pulse oximeter testing chamber, the result will be shown The contec product's housing use ABS matiral,the fingertip clip use silica gel mairal,is soft and easy to apply There is a screen protector on the glass which may be removed before use. You may see some scratches which are only present on the plastic removable screen protector. Ambient light immunity: < The difference between the value measured under artificial or natural light conditions in the room and the darkroom is less than ± 1%. Brand : CONTEC Package quantity: 1 piece Dimensions: 57 (L) 31 (W) 32 (H) mm Device weight: approx. 50 g (with batteries) Power supply : DC 2.6V - 3 , 6V Power consumption: less than 30 mA Battery life: two batteries can work continuously for 20 hours; the theoretical figure is 36 hours. Power: Batteries (included) Warranty: 2 Years