The Strato II is a transmitter and receiver based flash trigger system. These units take two AAA batteries, operate on 2.4 GHz and offer four channels to choose from along with four groups. The operating range is rated at over 150 meters.
My favorite feature of these guys is the TTL pass through. I find this feature the most useful when I am using my Nikon SU800 as a commander and I want to place a light or two out of the line of site of the transmitter. I can use the SU800 on one of my cameras and make whatever adjustments needed from the camera position and not worry about my accent light being hidden from the SU800.
Since the Strato's are powered by two AAA batteries they have a nice and slim body that is in no way obtrusive and takes up very little space in your bag. One thing to keep in mind is that the Strato II's are not transceivers and require both a transmitter and a receiver in order to correctly operate.
Let's take a look at the transmitter first. On the top of the unit you have the shutter button, status LED, and the camera hot shoe connection. On the left side you have the channel selection switch and test button. Over on the right side you have the 3.5mm PC input port and the power switch. On the back of the transmitter you have the four group selection switches. Finally on the underside you have the battery door, a locking ring, and a metal hot shoe.
The controls of the transmitter are laid out very simply and intuitively. Once you have the transmitter locked into place on your camera you have easy access to all of the controls
The Strato II receiver looks like it's made from the same mold as the transmitter, but it still has a few differences. On the top you have another shutter button and status LED. On the left side you have the channel selection switch and a test button. Over on the right side there is the group selection switch and power switch. The back of the receiver has a DC power port, 2.5mm accessory cable port, and a 3.5mm PC sync port. The bottom has the battery door like the transmitter, locking ring, a ¼ inch female thread, and a cold shoe mount.
Another point of interest about these units is that they are compatible with the Phottix Strato 4 in 1 triggers, but they only work together on channels one through four.
After using the Strato II's for a couple of months now I have not had any problem with them at all. They do all that they claim to. The TTL pass through option is something that I wish more manufacturers would include. In my opinion this is one of those features that put the Strato II's above the others.
The only draw back I see in these units is the fact that they are not transceivers, but that is just a personal preference. That being said, if Phottix puts out a transceiver based trigger system built on the Strato II design and features they will have a super trigger on their hands.
All in all the Phottix Strato II's are great transmitter and receiver flash triggers that are rock solid in their performance. The use of common batteries and a sturdy build make then great contenders in the battle of the triggers.