Yes, you can use the o-ring if you want to - some do, some don't. Does help with positioning the air holes. That paste in Noalox (anti-oxidant). Just dab a very little bit onto the tip of you firing pin every now and then. Helps prevent sparkling, especially if you go dark sub ohm.@Rob Fisher i have two questions if you can help me with it. Do you use a o ring under your cyclops rda like the reomizer and what is this small tube of paste i got with my reo?