THERMOMETER K-type Thermocouple ( 51, 52)   Large LCD display ( 18.5mm)   Dual thermocouple input ( 52, 55II)   Differential temperature ( T1-T2) ( 52, 55II)   0.3% + 1? basic accuracy ( 51, 52)    or display ( 51, 52)   Maximum Record ( 51, 52)   Reading Hold function ( 51, 52)   Triple 4 digit large LCD display shows any combination of T1, T2, T1-T2 plus  MIN, MAX and AVG. ( 55II)   Triple 4 digit large LCD display shows  main reading plus MIN, MAX or AVG. ( 53II)   MIN, MAX, and AVG display with Real  Time Stamp ( 53II, 55II)   Auto Calibration with excellent accuracy ( 53II, 55II)   Measure K, J-Types of thermocouples  ( 53II, 55II)   Selectable ? , ? or K reading ( 53II, 55II)   Easy to use panel design ( 53II, 55II)   Data logging up to 16, 000 records ( 53II, 55II)   Optical RS-232 interface ( 53II, 55II)   Auto Power Off with selectable time  setting ( 53II, 55II)   Protective Holster with tilt stand  Bead probes included  Optional optical RS-232 cable and  Win DTM50 software ( 53II, 55II)