They are tough, inexpensive and they work! These flash triggers, the 'Yongnuo YN-622C E-TTL Flash Trigger' they have made my life of shooting photos much easier. Here are all the reasons you should buy them:
1. They have wireless ETTL, which is to say they automatically adjust their power to create a well lit image. That eliminates the need to go full manual and spend half the time spent shooting adjusting camera settings.
2. They have a laser beam coming out the front. It shoots a target of red light to help the camera focus. And you know what. It works! When shooting fast paced events in the dark, be it music, dance, or any performance, it focuses within half a second. Prior to having these my camera simply didn't focus.
3. They have high speed sync. Where previously with my cheap triggers I could go no higher than 1/250th of a second, which is unfortunate when shooting in sunlight and using off camera flash. I can now use flash all the way up to 1/8000 of a second. Put into use, I am able to keep my aperture set to a F 1.4 on my 50mm while adding a little artificial light. Win!
4. They work!! Not once have they malfunctioned, misfired or not worked and I've had them for nearly a year.
5. A pocket wizard equivalent, with wireless ETTL, high speed sync and zone control costs over $200. EACH!! and these are $50 a piece.
6. They are interchangeable. I can have the same trigger on my camera, or on a flash. They are all the same.
7. If I decide to shoot manual, I can adjust the brightness of the flash on my camera through the flash menu. I don't need to access the flash physically to change settings. So that allows me to place it in odd places and not have to touch it till I'm finished shooting.
I have 4. I spent under $200 for all of them.
You can buy a set of two for $85 on Amazon.