Yes Nitro-X I'm pretty sure about the Polymer/synthetic frame.
If you look at the above images, you can see the mould line and scratches/marks on the frame.

Also, the way the frame's firing mechanism is retained and is removable (from the Frame/Grip), and also the material the Frame/Grip is made of, reminds me of my Sig, Mosquito .22LR pistol.

Regards
Homer