A/3K-PM - The Pipe Mount probe is specially designed to fit pipe contours of 1? diameter or less.  The unique shape of the probe allows for a strap to securely install the sensor to against a pipe.  In addition the convex contour aids in the temperature transfer allowing for a more accurate signal.

A/3K-PO-4" - 3K Ohms @ 77 Deg F (25 Deg C) Thermistor Probe Only