Newman Medical PPG probes, like our Doppler probes, have been designed to provide excellent sensitivity and durability for everyday use. The unique DigiDop PPG Vascular Probe can be used on any DigiDop and provides an audible signal/beep for each pulse. It is an excellent choice for taking a toe pressure for the Toe/Brachial Index exam and also in any application for monitoring of blood flow at the extremities. The PPG probe's sensor is independently replaceable. Made in the USA in Colorado. Each Newman Medical Doppler and probe must pass a series of comprehensive tests to assure quality and the durability of each product.