I've used aquarium filter (fluval) to
mod a cart for the eGo. You want it about 1.5 times bigger around so it compresses, and about the length of the cart for a full
mod. I cut it off even with the top, so the addy will push against it slightly and make good contact. Worked like a charm for me. An old manicure set makes handy tools - tweezers for adjusting filler, scissors for cutting any strays for flyaways that may pop up during use.