PeakTech TF-56 - Universal Temperature Probe -40 +204°C with 4mm Plugs Universal Temperature Probe -40 +204°C with 4mm Plugs Universal temperature probe suitable for liquids, surface and air measurements. This temperature probe is typ-K-thermocouple (NiCrNi) suitable for all the PeakTech thermometers with 4mm sockets. $4.88 Add to cart