Even before I bought it, I knew that I'd be replacing the pressure gauge on the Marauder. The one that came on it is passable, as almost all factory pressure gauges are, but not great. The consensus among the various forums was that the Dwyer gauge was the best of the smaller diameter gauges that would just drop it. The brown truck brought mine today so I swapped it out tonight. It's much easier to read precisely, and as a bonus it matches what the pressure gauge on my FX pump says pretty well also. Here's a shot of the two side-by-side. Sorry for the glare from the camera flash. I was in a hurry taking the picture.
I bought it directly from the Dwyer Instruments website. It's part number SGC-15.
http://www.dwyer-inst.com/Products/Prod ... e=Ordering
The gauge itself only costs $9.50, but it costs $8.75 to ship and $1.57 tax for a total of $19.82 to my door. I somewhat wish that I had just opened up the hold in the stock a bit more and used one of the larger, more detailed gauges for that price. For what this gauge is, though, it's great.