Testo-Testo-0636-2161-Robust-Humidity-Probe-Testo-0636-2161-P-The-Testo-0636-2161-is-a-Robust-Humidity-Probe-for-taking-measurements-up-to-125-deg-C-&-short-term-up-to-140-deg-C-BR-The-12mm-diameter-can-be-used-for-exhaust-ducts-&-for-measurement-of-material-equilibrium-moisture-e-g-bulk-goods-Ideal-for-use-with-the-Testo-635-Thermo-hygrometer-P-Testo-0636-2161-Humidity-Probe-20-to-125-deg