The Onyx 9500 is a great oximeter to purchase for home or office use. It can be used for clear, precise, and accurate readings of blood oxygen saturation. It does not require additional sensors of any kind. It is highly portable and can go anywhere throughout the course of a day. Many clinicians use this because it is well trusted and is accurate, plus or minus two degrees. It is even small enough to fit into a purse. This oximeter can also work for my someone that has large or small fingers. It is a proven and safe piece of equipment.