I can't help you out with that exact bit (hopefully someone more knowledgeable will come along) but I can tell you that ANY bit with shanks is a curb and not a snaffle.
"Snaffle" refers to the 1:1 ratio of pressure a snaffle uses to communicate with the horse. Aka, you pull with one pound of pressure, the horse feels one pound of pressure.
A "curb" (like your bit) uses leverage to communicate with the horse. The amount leverage is determined by the length of the shank so if you have a bit with a 5 inch shank, your 1 pound of pressure will create 5lbs of pressure in the mouth, and so on - 2lbs of pressure, 10lbs of pressure, etc.
There are some very low leverage curb bits out there with very short shanks, but they're still curbs and should be used as such.
Often people use the word "snaffle" to describe the mouthpiece but that is incorrect. A jointed bit is not automatically a snaffle because it's broken and a bit is not automatically not a snaffle if it isn't jointed - ie the mullen mouth snaffle.
Hopefully that wasn't too overwhelming! :)
For an example, here's is my favorite "step up" bit. I use it on my mare when I want o ride in a curb and she loves it. The copper encourages salivation, it's slightly ported to allow a little tongue relief, the shanks are loose - allowing for limited cueing with one rein or the other should she decide to ignore my neckreining cues, the shanks are short - 5 inches - and therefore basically as gentle as you can get without shelling out $$$. The other thing I like is that if my girl is having a rough day and I'm needing to direct rein her a lot, I can just move my reins up to the higher slot and direct rein away. There is a tiny bit of leverage in that higher slot but it's probably something like a ratio of 1:1.25 vs 1:5 like the lower slot. NP Sweet Iron Loose Cheek Western Curb Bit 5in - Horse.com
Here's another good one I know some respected people on this forum really like: AT Low Port Loose Cheek Low Port Western Bit 5in - Horse.com