The 200DX I got came with 1.6, 2.0 and 2.4. Dunno what the heck the 2.0 is for, but the others are 1/16 and 3/32 respectively.

I ordered 1/16 tungstens when I first got the machine, and shortly found that I needed 3/32 more often, even working on thinner stuff. I'd say order the 3/32 if you're only ordering one, you can always sharpen them more acute if you find they're a bit big for an application. Kinda tough to thicken 1/16