You do realise thst it's called an rdta because its an RTA & an RDA?? You take off the glass and chimney. Attach the top cap directly to the chamber and bam you got a 3ml rda and if you got the mesh deck or velocity style deck you get a squonk pin too for a 30mm rda that squonks !! Sorry, i forgot to add. I TOTALLY AGREE. the grub screws are USELESS!! Had to switch it to the flathead screws almost immediately myself. Thanks 👍