I tried the herb cartridges with no success, How do you vape it? The only thing I can think of Temperature Adjustment. In my crafty the carts work great.I don't know how much it fits but I would say more than enough.
I had to buy herb capsules separately and I'm happy I did. I never use focus without one. I also got focus water tool that I use without water instead of regular glass mouthpiece.
cleaning is really easy when using capsule. the insides of the capsule stays clean after emptying. I don't know if it's because of "material" I'm currently using for vaping or the material of capsule...
for dimensions check official site.