I would recommend this product to anyone interested. I was told by My Pulmonologist to monitor my oxygen level because of my health conditions and he told me to order this one specific oximeter ( Santa medical finger pulse oximeter model SM1100-S) which is the one he uses. He told me no need to spend big money on other brands. He uses this one all day everyday and never had an issue. I've had it a week and it works perfectly. I love it.