Does anyone know if this mug is big enough...
Does anyone know if this mug is big enough to fit a small canister in the inside? if not what is the difference between this and the 450 and would the 450 be able to hold the small canister??
To answer your second question first - the difference between the 600 and the 450 is volume. The 600 is a 600ml cup (about 21oz) and the 450 is a 450ml cup (about 14oz). The 450 is SMALLER than the 600 (and weighs about .5oz less).
Now for the first question - the smallest canister that I know of is the Jetboil Jetpower 100g canister. It's dimensions are 3.5" diameter by 2.5" tall. The dimensions of a 600 are 3.8" diameter by 4" tall. So YES, this canister will fit inside the 600. However it will NOT fit inside the 450, which has a diameter of only 3.4".
The Snow Peak 110g canister will fit @ 3.25", but here's a hitch to it, the 600 cup tapers in at the bottom, so it won't go all the way down and will be snug, so if you're also hoping to nest a small stove like the Gigapower or Litemax, the stove will have to go in first. The 3.5" Jetboil 100g canister won't fit. It gets hung up on the lip of the cup because the 3.8" diameter is measured on the outside of it.
The smaller Snow Peak diameter canisters will all fit easily into the Trek 700 pot, and if you want to use a full sized canister like an MSR, you'll need to go up to the Trek 900.