I purchased lr boge cartos from 2 different places. One of the individual cartos has a sticker on it that says 2.0 lr (I know it means low res 2.0 ohms) and the other one says 510D lr. Im asking about the "D". I think it means disposable. I know you can clean cartos, but I thought they were disposable? Will the ones marked with the D not last as long as the ones that dont have a D on them? Thanks.