I ordered a ton of 801 blank carts, and they are different than what I am used to. At first I thought I had ordered the wrong thing, but I also got some 901 carts that were the same.
I could get the cover off the 901 carts, just by twisting and gently pulling.
With the 801 carts, the cartridge came off in the cap, leaving only the mouthpiece (a nice, soft rubbery one, btw) in my hand. I was able to extract it with a pair of flat jewelry-making pliers--and sort of mangled it. It is still usable, but there has *got* to be a better way.
Is there a trick to getting the caps off that I am missing?