Extech RH350 Dual Input Hygro-Thermometer PsychrometerExtech RH350 SuperHeat Psychrometer SuperHeat Psychrometer Two Type K External Probe inputs for Superheat Plus built in memory stores up to 99 data records Key Features: Superheat differential measurements: T1 T2, Air T1, T1 Dewpoint Dual Type K external temperature probe inputs (T1, T2) Simultaneous display of %RH, Temperature and Dew point or Wet Bulb or External Probe Temperatures Built in RS 232 interface uses optional Windows 95 98 2000 ME NT XP