Nicwell Fingertip Pulse Oximeter Blood Oxygen Saturation Monitor $12 at Amazon
Amazon with JiangKou.. has the Nicwell Fingertip Pulse Oximeter Blood Oxygen Saturation Monitor with LED Display and Lanyard (Royal Blue) for $13 - 10% off coupon (check "Save an extra" box) =
$12 with free shipping on $25+ or with Prime.
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