Tons of manuals available online for this. But this is definitely the top of the line model. Works extremely well. Breath test is in the last picture. Item has clearly never been taken out of the box unless with extreme care. All parts look brand new.

Mass of details copied from a manual online:

Phoenix Humiport 05/10/20 Large Display for Easy Reading The Phoenix Humiport line of ThermoHygrometers offers the restoration professional the optimum balance between cost, accuracy and response time. Each Humiport Meter offers a large display for easy reading, and all of the important restoration information including, temperature (either F or C), relative humidity (%), dew point (F or C) and the popular “grains per lb” mixing ratio. There is even an “altitude” input that makes sure the grains calculation is extremely accurate. A listing of altitudes by state and (some) cities is available at www.usephoenix.com, so you can set the meter to your specific area. The Phoenix Humiport meters display conditions, calculate data and can display: MIN (minimum), MAX (maximum), AVG (average) and HOLD. All Phoenix Humiports (5, 10 and 20) also feature 2 point calibration and offer 2% accuracy for relative humidity and have the largest display in the industry. They also include a backlit display option and auto-off feature. The Phoenix Humiport 20 has a detachable probe with a coiled cord that extends over four feet to eliminate problems reaching difficult areas or reading the meter display when the probe is recording areas over your head or near the floor. Features • Fast response • Accurate +/- 2% RH • Grains/lb display • Dew point • Large display • Min/Max/Avg. and Hold functions • Altitude input for gpp calculation • Time/Date display (10 & 20) ThermoHygrometers Humiport 05 Humiport 10 Displaying temperature and mixing ratio in grains per pound. Humiport 20 www.UsePhoenix.com  Therma-Stor LLC 02/17 Specifications subject to change without notice. Affordable Accuracy and Response Time Phoenix Humiport The Phoenix Humiport ThermoHygrometers provide accuracy, fast response time and a variety of meaningful functions and displays. A unique ‘thumb wheel’ is used to select the desired data. Push in to enter selection and power “ON” and “OFF” Toggle up for selection of: HOLD, MAX, MIN & AVG Toggle down for selection of: g/m3, %rH, dp°F, dp°C, g/Kg, and gr/lb (gpp) 
Humiport 05/10/20 
ThermoHygrometers 

Functions/Features 
HUMIPORT 05 /10 / 20 
Temperature 0.1° / 0.1° / 0.1° 
Relative Humidity 0.1% / 0.1% / 0.1% 
Dew Point 0.1° / 0.1° / 0.1° 
Mixing Ratio 0.1gr/lb / 0.1gr/lb / 0.1gr/lb 
Date/Time No / Yes / Yes 
US / SI units Yes / Yes / Yes 
Auto Off No / Yes / Yes 
Remote Probe No / No / Yes 
2 Pt Calibration No / Yes / Yes 
Backlit Display No / Yes / Yes 

Specifications: 
Measuring Values 
Humiport 20 
Sensor type Relative Humidity HC101 
Temperature NTC
Measuring Range Relative Humidity 0 to 95% 
RH Temperature -4° to 122°F (-20° to 50°C) 
Dew Point @ 68° - 5° to 66°F (-15° to 19°C) 
Mixing Ratio @ 68° 5.46 to 98gr/lb (.78 to 14g/kg) 
Accuracy Relative Humidity ±2%
RH Temperature ±0.7°F@ 32 to 104°\±0.9°F (±0.3°C @ 0 to 40°\±0.5°C) 
Dew Point @ 68° ±(7.79 to 0.81°F) ±(4.33 to 0.45°C) 
Mixing Ratio @ 68° ±(2.03 to 2.8gr/lb) ±(0.29 to 0.4g/kg) 
General Supply Voltage 9V 
Battery 4 x 1.5VAA Alkali-Manganese Battery 
Battery Life Typical >500 hours 
Display LCD 3.5”x 1.9” 
Working Temperature Range 32° to 122°F (0° to 50°C) 
housing: 32° to 122°F (0° to 50°C)
probe: -4° to 122°F (-20° to 50°C) 
Housing/Protection Class ABS/ IP40 ABS/IP40 
Dimensions w/filter cap 6.9”x 1.9”x 1” 5.7”x 3.3”x 1.5” 
w/out filter cap 5.5”x 1.9”x 1” 
Humiport 20 cable 4.9’ 
Weight 0.5 lbs 1.0 lbs