1. Place the pulse oximeter on the top of your wrist with the USB port pointed toward your hand. Secure the wrist strap, so the pulse oximeter stays in place.
2. Place the ring sensor on the base of your index finger or thumb. If the ring is too tight, you can use a different finger.
3. Plug the ring sensor into the USB port and turn on the pulse oximeter by pressing the small power button on the side