I gave up on trying to fit the screen in and just been using the other stem trying to learn how to use the stempod and what watt setting to use.Try the fourth video down by Lamart "make basket screens fit all stems"
The one above also shows how to fit a 15mm screen for stem packing (if you want to try stem packing the blue one)
The stem packing video is pretty interesting because I have extra screens but not sure what size they are. They do fit in the stempod chamber though. How far down am I suppose to push it exactly?