From what I can find on their website is the FLir One comes with a Lepton Camera that allows it to take the thermal imaging. The data sheet for the camera can be found here.
Features
■ Dimensions:
8.5 x 11.7 x 5.6 mm (without socket),
10.6 x 11.7 x 5.9 mm (including socket)
■ 51-deg HFOV, 63.5-deg diagonal
(f/1.1 silicon doublet)
■ LWIR sensor, wavelength 8 to 14 μm
■ 80 (h) × 60 (v) active pixels
■ Thermal sensitivity <50 mK
■ Integrated digital thermal image processing
functions, including automatic thermal
environment compensation, noise filters,
non-uniformity correction, and gain control
■ Optional temperature-stable output to
support radiometric processing
■ Export compliant frame rate (< 9 Hz)
■ MIPI and SPI video interfaces
■ Two-wire I2C-like serial-control interface
■ Uses standard cell-phone-compatible power
supplies: 2.8V to sensor, 1.2V to digital core,
and flexible IO from 2.5V to 3.1V
■ Fast time to image (< 0.5 sec)
■ Low operating power, nominally 150 mW
(< 160 mW over full temperature range)
■ Low power standby mode
■ RoHS compliant
■ 32-pin socket interface to standard Molex or
similar side-contact connector
What are good specs and what should we look for when buying a thermal imaging camera?