For a list of all currently documented ZyDAS chipsets with specifications, see ZyDAS.
"M01-UG265-X20" is silkscreened on the board in the FCC photos.
This FCC ID also covers the WUG2654 - a model with a 4 MB Flash chip on-board (presumably for mass storage mode for auto driver installation).
The FCC operational description includes a block diagram for the device.
- The RFIC is specified as an RFMD RF2959.
- The PA module is specified as an SiGe SE2525L.