polar heart rate monitor battery

{"title":"Private TFT Screen Finger Clip Pulse Oximeter Heart Rate Blood Oxygen Monitoring","imgUrl":"https:\/\/img.silkroadsl.com\/nimg\/17\/57\/7a99b8f8e090c876b974e35474ec-200x200-1.jpg","attrs":{"Price":"$4.58~7.78\/pc","Brand Name":"Responsafe","Model Number":"TFT oximeter","Minimum Order Quantity":"100pcs","Delivery Time":"1-4 working days","Certification":"CE","Place of Origin":"China","Payment Terms":"T\/T, Western Union, trade assurance order","Supply Ability":"1000pcs per week","Packaging Details":"Individually box package, every 100pcs in one carton, carton dimension 46*37*25cm, 7.5kg","Product Name":"Private TFT pulse oximeter","Usage":"SpO2, heart, pulse rate measure","Display":"TFT","SpO2 Display":"35%~100%, \u00b12%","Pulse Rate":"30bpm~250bpm, \u00b13bpm","Power":"2pcs of 1.5V AAA removable batteries","Package":"100pcs\/carton","Carton Weight":"7.5kg"}}