The HDX-OTP handles are compatible with all PR-13 and PRTF-13 probes which include a standard sized quick disconnect connector (round pins). The handles are made of rugged die cast aluminum, and include retractable extension cables that extend from 1 to 5 feet. The cable is supplied with stripped leads standard, optional connectors are available. These handles are great for use with any of Omega's line of hand-held or other meters and thermometers.The PRX-NP-100-E-12 Penetration Probe incorporates a conical tip for easy insertion into soft and semi-frozen materials. The PRX-AP-100-E-12 Air Probe includes a perforated tip and exposed RTD element for measurement of air or gas temperatures. Both the NP and AP probes contain 100 Ohm, Class A DIN Platinum elements.