Could somebody please advise me if it is possible to screw in a polarizer lens to these lens? It has a 105mm thread on the front. thanks

I can think of no reason why you could not screw on a threaded 105mm filter, although I imagine most folks will be using matte boxes and 4x4 filter holders with these lenses...

Thank you Chris, I did find a few options for CPL at 105mm, such as B+W and Sigma filters. :)