Mop is correct, you just need airflow (usually provided by that hole in the side of the 901 atomizer). Though they're available, you don't absolutely need an adapter. You can use the staple mod or do the dremel cut into the 901 connector. If you're nervous about cutting into your new mod, as I was, you can also make your own adapter from a 901 manual battery charging adapter extension (I bought 3 for this purpose @ $1.95 each).
If you've already got a 510, you might want to get the mod with a 510 connector and get a 510 to KR8 adapter so you can still use the 510 atties and carts you have already have as well as the KR8.