OXY-500A is the most economical, reliable high performance and easy to use pulse oximeter. Utilizing as auto gain control, it not only generates a fast response but also an accurate measurement result by greatly reducing possible errors when examining different reces. The LCD provides great visibility of plethysmographic waveform, integrating a signal strength indicator plus on-screen trending. Easy-to-read display at any time. DC battery available with maximum 4 hours of operation. User friendly and transportable in compact design with handgrip. Perfect quality for ER, OR ambulance and more.