OK. Solution to not using the cone. You know the little adapter that TW sells to use the wall charger? Well with that used as an extension, it acts as a 510-510 adapter. With that in and then the cone over the adapter, the 306 with a drip tip from NHaler fits perfect. It allows me to use the cone to hold my lanyard to hang my Tornego around my neck. Perfect little dripping machine for on the go. Then if I want, I can switch to cartomizers or atomizers as needed. BTW, that 306 is a beast. It has outlasted every other atty I have used. Period. I bought two of them and the first is still kicking ....(s)!