Sorry to be an annoying bugger and asking too much questions but biting a little hard (unresistable for me when not vaping but its in my mouth) a piece detaches from the cartridge mouthpiece of my DSE901. It is not destroyed doing this and can be popped back on and is the hole to suck through. I done it twice today whats it for and is it needed?? I think more vapour comes through without it but I am not sure anyone know?