Airsoft Nozzle O-Ring conversion

FOR GBB ONLY
Since i ordered a WE Tech P320, i didnt like the cup head seal the nozzle assembly came with, so i designed a convertion piece that replaces the current cup head seal with a nice o-ring that you can find around. Since i couldnt risk to make an exact inner size (where the o-ring would be placed) i made it with a big gap on purpose so you can add a string or a material to "shim" the o-ring so it has the desired expansion for your gun.

Im NOT sure if itll fit ALL airsoft guns, its more likely to fit a WE Tech one. If it fits your gun, please let me know!

Sanding and shimming might be recommended and required because of printer tolerances.