i posted the same a while ago: http://motorbicycling.com/f34/chain-...ght-12689.html
the one i got came with two different pins, one that fit bike chains, and one that fit motor chains. all the one's i've seen since have 2 bigger pins.
i got one for my buddy, and just used a grinder to make the pin skinnier.
on mine, the smaller pin busted in half. the links don't line up perfect, so if you're off a little, you can damage the chain, or in my case, the pin.
luckily, it was still long enough to use after i smoothed out the broken tip.
i still like it. it's the best chain breaker i've found so far.
also, after adding links to a chain, make sure they move freely. usually they're a little tight. you can flex the chain back and forth, or stick a screwdriver inbetween the link and tweak it a bit. just make sure it doesn't bind, or you'll have problems.