Water trap suggestions?

I was lookin at bagginit.com and it showed this water trap that works great from campbellhausfeld.com So I checked it out and it was only $13 compared to the $40 that SD is selling the SMC water traps for. So which way should I go, get the cheaper one or the SMC one?
If you go to that website above, search for mini general purpose filter and you'll find it.