I've used several other brands besides the scada, but I don't recall the names other than that penny one. I just settled on the scada one because it was less breakable.
I did searches on the net, and parazappers never showed on any of them. I woulda went with his model most likely. I wasn't really active on CZ then and so didn't know him yet. And if I were to buy one now, it would be one of his. He tests them off the roof of his garage onto the concrete driveway---I'm pretty sure I woulda had a hard time breaking them, since mine only fall a couple feet to a tile floor. The couple I broke I probably could have sent back and gotten fixed, but it was easier to just replace them.
After breaking the second one, when I was searching for a replacement, I found the SRG-4, and bought it because I wouldn't pull it off on the floor. It seemed a good price (seems it was more expensive the first time I bought it) and it seemed a good unit. It did what I need. I honestly think, if used properly, most any of them will, including that 9 volt battery one, a lot more work, but it will do the trick.