Fingertip pulse oximeters clip onto a finger and display oxygen saturation (SpO₂) and pulse rate. Three models are stocked here, and the differences come down to display, connectivity and intended user.The Finger Pulse Oximeter is the simplest, with a bright LED screen, one-button operation and two AAA batteries; its listing states it is intended for trained personnel in hospitals, clinics and care facilities rather than consumer or at-home use. The Fingertip Pulse Oximeter with OLED Display adds a six-mode adjustable screen and Bluetooth connectivity. The Bluetooth Finger Tip Pulse Oximeter carries the fullest specification: an OLED display with four orientations and six display modes, plethysmogram and blood perfusion index, adjustable alarm parameters, Bluetooth to iPhone and Android, and auto power-off after 10 seconds without signal.The LED and Bluetooth models both run on two AAA batteries, so keep spares; the Bluetooth model ships with batteries, a carry case and a lanyard.