The FaceLake FL400 Black finger pulse oximeter is a lightweight, portable device used for measuring both heart rate and blood oxygen levels or SPO2. Simply place your finger inside the vinyl sensor and have these measurements instantly displayed on a large LED screen. Features a battery-saving automatic power off function. We stand by our products with excellent customer service and a one-year warranty. NOTE: this product is intended for sports and/or aviation use only and is not a medical device.. From the factory, there is a clear screen protector which can be removed before use