I use a Parker Jotter that has a cap that slides to activate the pen (not a twisty). I use the Parker refills. I don't like the Fisher refills as they are blobby and skippy especially the colored ones. The Jotter comes in 2 diameters and several materials: Gold, Gold plate, Sterling Silver, Titanium, stainless steel, and stainless & plastic. Every time you activate the pen, the refill is rotated 1/4 turn. This evens the wear on the ball socket.