Pure component vapor pressures at 293 K to 328 K and binary vapor-liquid equilibrium (VLE) at 68.93 kPa have been measured for the two diastereomers of 1,1,1,2,3,4,4,5,5,5-decafluoropentane (HFC-43-10mee) using an ebulliometer. VLEs have been measured as a function of overall composition for binary mixtures of the high-boiling diastereomer of HFC-43-10mee + tetrahydrofuran (THF) at 26.69 kPa and 45.51 kPa using an ebulliometer. The VLE data were correlated using the NRTL equation. The coexistence curves for HFC-43-10HB + THF at 45.51 kPa exhibit a maximum and a minimum in temperature, establishing the existence of double azeotropes at this pressure.