IMS Gaggia Precision Shower Screen ø 55mm - GA35WM From  £14.04

Much better than the standard Gaggia screen. Transfers much less coffee back into the group head.
Works perfectly

Since I own this plate, the backflush isn't that dirty any more. I don't spend that much time (compared to the standard shower plate) to clean the shower plate after the shot. The puck doesn't stick as it has stuck beforehand.