I'm getting this A LOT in my data recently, more than usual. What could be wrong and how do I fix it? I gotta know deez phone models 
Run a click report, then sort by MF/Name/Model, then take a look at the user agents - and often you will see model numbers and other handset identifying info in there.
From what I've seen, the UNKNOWN handsets are the newest models, possibly because the imobitrax database hasnt been updated to identify them yet.
GS
Use 
Thanks for the quick response. Is there an option for user agents or do you just mean the output from sorting the data?
I'm seeing some of them classified under certain brands (e.g. Nokia > Unknown Android > Unknown Android or ZTE > Unknown Android > Unknown Android) but the vast majority are Unknown > Unknown Android > Unknown Android. 
I think you will see this quite a lot unless you use premium services like handsetdetection.com.
If possible try to use tokens from the traffic source passing that info, it will be way more accurate.