Without looking at the specific device, I'll give a generic answer.
If you have the manual for the device, rarely it will tell you how it is modulated or what frequency it uses.
The next place to check would be the FCC. If the device is type accepted, it should have a FCC registration number, and you can look up technical documentation on FCC's website using that number. This should at least give you a frequency and bandwidth, and usually a description of the modulation in broad strokes. (Sometimes, in more detial.)
Lastly, and possibly using the results from above (or maybe not, if you don't have or know about the device), there are several SDR software packages designed specifically to help with reverse engineering modulations. These are described in the rtl-sdr.com blog and possibly in the software review section, as well as links to some tutorials and examples.
The signal identification wiki https://www.sigidwiki.com/ may also help, with lots of examples of identified and unidentified signals.