Until recently*, the penstyle had the largest capacity cartridge of the
traditional three-component e-cigs
†. The DSE801 is
one of the penstyle models. Others are RN4072, BE112, and Joye302, all of which are compatible with the 801. The other penstyle model is the M201: its atomizer is not compatible with the others' batteries, but I
think all the carts are interchangeable. [Check the respective
Model Specific Discussion forums and/or supplier to be sure.]
*
Totally Wicked now offers the 510 Titan
MEGA cartridge, which has much greater capacity than a standard Joye 510 (aka Titan) cartridge. [NOTE: It will only fit the Titan MEGA
atomizer.] I'm not sure how it compares with the penstyle cartridge. Probably similar.
† Cartomizers (integrated cartridge and atomizer) – used in two-component e-cigs like Kr8, E9, and GreenCig – have quite a large capacity, especially the 1/4"-longer GreenCig carts. They rival any of the above. Actually, when used as originally intended, they
never need to be refilled, just replaced. But since that can get expensive, most people do refill them. Find out more in the
KR808D-1 Model Specific Discussion forum.
And then you can do what I (and many others) do: Just forget cartridges and drip (directly on the atomizer). This entails frequent but rapid handling of juice bottles: pop off the mouthpiece, open the juice bottle, drip, drip, drip, close the juice bottle, put the mouthpiece back on, vape. [It took me a lot longer to type that than to do it.]