Hi everyone , and happy 4th . I just joined this forum a few weeks ago , and have only been vaping , a month and a half . (Wife too) In the past 2 weeks , I have become , what I think , is known , as a mod ..... . I have purchased 5 , off the classifieds , in that time . Now I know how women feel , at ashoe store , with a bogo sale . Anyway , have learned alot from the forums , but still lacking a few things . One of the mods I bought has a 901 connector , so I ordered a 510 adapter (I prefer 510 ) Now as to a few questions . First , I see ads on vendors sites for drip tips , 510/901 .Does this mean the same tip , will work with both atty's , or carto's ??? 2nd question , I've seen several youtube , review video's Grimgreen , is one of the reviewers . Use a 306 atty. on a mod , and I see that there is , in fact a 306 drip tip , available on the sites . What is the advantage of a 306 type atty , over a 510 ??? and are they size specific, or does the 306 , thread into a 510 connection ??