MECHLYFE x Fallout Vape XRP RTA Advanced Kit MTL Edition comes with 24mm diameter and 3.5ml capacity. It features single coil / dual coil deck for option. And there are five inner adjustable airflow holes on the single coil deck(1.0mm, 1.2mm, 1.4mm, 1.6mm, 1.8mm). MECHLYFE XRP RTA is compatible with voopoo PnP coils by Bridge system. XRP RTA utilizes adjustable MTL & DTL airflow ring, 510 MTL drip tip and 510 DTL drip tip for MTL & DTL vaping.