Model 900 is a pulse oximeter with waveform designed for supporting an optional RS23 2 Serial Port, an Analog Output, and a Nurse Call feature. Features: Desktop Pulse Oximeter that is ideal for most continuous monitoring applications Bright LED displays indicate Oxygen Saturation and Heart Rate from any angle & in most lighting conditions Audible Pulse Tone varies in Pitch with rise & fall of Oxygen Saturation Audio/Visual Alarms for Saturation and Pulse Rate Simple Keyboard layout makes units User-Friendly Unique Averaging Sequencing Technique updates values & provides faster Response Time Continuous Battery Condition Indicator