At DietSmoakes is it the ones called "DSE901 /4075 Blank Empty Cartridges" Sku:901emptycarts? Do they fit well on the 510 or are they very tight?
Yes. Those are the ones I ordered (no guarantee that Parked will stay with that type - you might email/PM him if you want to make sure) ...and they fit well on the Innovapor 'new attys'** which were a tad oversized, and they are a very snug fit (some force needed to take on and off) on the regular 510 attys at first, but as things get heated up they become just tight. The regular 510 carts can get very loose sometimes. It's all in the tolerances of both parts, of course a 1000th can make the difference. But.... they do fit. I'd rather have it be a tight fit. One can always shave a bit off but it's harder to add on without introducing some other material that might not be right for vaping/inhaling.
**About a month ago, Innovapor introduced 'new atomizers' for the 510 that were supposed to last 3x longer than the current ones. They carried two types - the titan with the brass band and the 'classic' without the brass band. The 'new attys' didn't have a brass band and ended up were oversized. At one point you could designate which of the three that you wanted. I haven't checked recently. But the regular 510 carts were too loose for the 'new attys' and the solution was to get the 901 carts. The problem was, that there were (at least) two types of 901 carts - the "0" style and the "D" style. Only the "0" style fixed the problem with the new attys. If you don't have those new innovapor attys then that isn't a problem as far as size goes. But there is a difference between both the 510 and the 901 styles in the flat tips - the mouthpiece end on the "D" style can be very loose and come off in your mouth - someone swallowed one - that can be best fixed, imo by just removing it. I only use the "0" style because I like the thicker flat/whistle tip and the end piece is solidly fixed. And the "0" style is better, imo, for the straw mod.