Hello fellow e-cigers, I am a recent convert, just got my stuff 2 days ago, a pen style from thesmokesafe. While changing cartridges today I noticed a small latex rubber type "cup" or cover that came loose from whatever it was attached to. After further investigation, it appears it comes with the cartridge (after looking at an untouched cartridge, I see one down at the bottom of the cartride cover). I also noticed one inside my atomizer but I probably put it in there when I shoved in the first cartridge, I removed it though it vaped fine with it in there. So my question is - is this thing supposed to be in there while operating the e-cig or am I supposed to remove them before inserting the cartridge into the atomizer part? Perhaps it's just there to help seal the cartridge so it doesn't dry out in storage? Please help the newb.