First of all, they're found here. I haven't seen anyone do a write up on these here so I figured I'd take the time to do a quick review based on my experience with them over the past few weeks. I decided on the Cactus V4's mostly due to the cost being so much less than the Pocket Wizards or Cybersyncs, and also because they are the newest version of Cactus triggers following the V2's (no V3 for some reason) which I hoped they'd resolved the issues of the past version. In reading reviews of both models, the biggest and most consistent problem seemed to be the reliability rate at which they actually triggered the flash to fire. I had already ordered mine when I met a few people shooting V2's which proved to be both unreliable and cheaply made (no mods done, and one guys was missing some of the internals causing it to not work). Needless to say, I was worried I had made a bad buying decision. Plus, my intent was to use Nikon's CLS system with 2 Vivitar 285hv's on the V4's, which was flawed because the systems cannot work together due to the transmitter blocking the pop up flash on my body. I still knew I wanted to try them out to see if the V4's would be more reliable and I ordered two more receivers as a gamble (one for SB600 and an extra for the future) which I figured I could sell immediately afterwards if they sucked that bad. Upon receiving them, I was surprised they came with only a bubble lined envelope surrounding the box, but I assume this cuts down on the shipping cost from Hong Kong. The product boxes all have nice protective padding in them so I guess it's not a big deal they came in envelopes, but with many people complaining about them showing up DOA, they might want to look into alternate shipping materials. Anyways, after inspecting them, they all appeared to be fine and I loaded the packaged batteries into the units and gave them a go. The new design of the receivers makes it so they run off of AAA batteries which are an improvement from the V2's CR2 battery. The transmitter runs off of a 23A 12v battery which is also easily replaced. It's nice they give you these batteries to start, but they are crap, and you'll want to have fresh batteries in them as soon as you can (which I will explain below). The battery cover on the units is a bit flimsy and can have trouble staying on so a small bit of tape would ensure you don't lose it in a shoot. The plastic on all the units feels cheap because it is but these certainly look better than the V2's and they are more practical in terms of design. For example, the V2's receivers were set up vertically with a screw-tight tilt design, and the V4's are set up horizontally with the hotshoe mount sitting directly above the stand mounting threads (which is also a hotshoe that could be used for stands, etc). This means no more sagging flash, which was another complaint I often heard from the V2 users. The transmitter has an antenna built into it which can operate up or down, but I'm not sure how effective it actually is set vertically. Many people have complained that the misfire rate increases with the antenna set up, so I've just kept mine down, and it works fine that way. It does have a clean look to it though which should fit well with the design of most modern bodies. As for function, using them straight out of the box with the stock batteries produced expected results. I had a misfire rate of about 1 in 30-40. I hadn't really tested the distance, but they were definitely good for about 20 feet and the results were the same. After replacing the batteries with some fresh alkalines, the misfire rate was improved dramatically. I shot about 130 frames with two flashes the other night without a single misfire. I don't want to claim that with fresh batteries they are going to be as reliable as PW's, but I'm definitely not seeing the results I had when I first used them. Lately I've only been using them with 2 flashes due to breaking my 3rd, so I'll have to report back on the reliability when I'm running 3-4 flashes. All in all, for the small amount of money I spent on these (in comparison to the competition), I'm really quite impressed with them. I don't do any paid work with them, and nobody really recommends using them professionally, but for the person learning off camera flash as a hobby and on a budget, the money is would be well spent. One thing to keep in mind is that they are based out of Hong Kong so getting your product fast can mean spending a lot in shipping. It also means you'll have a lot of down time if you have to deal with replacement/warranty issues (which you may). Pros: Improved design on the receivers Quite reliable with new batteries Receivers use AA batteries 16 channels Inexpensive Cons: Plastic is cheap Not as reliable as PW's or Cybersyncs Made and shipped from Hong Kong Anyways, hope this helps some of you out if you've been considering getting into off camera flash and need an inexpensive wireless trigger solution. Feel free to ask any questions or post comments with your own experience with them. I understand that the user results on these vary greatly and if you have had a different experience with these, please share.