I got this flash today from mail. It is a manual flash (no TTL) but it's power is adjustable from 1/128 - 1:1 (7 stops) and guide number (iso 100, meters) 33. It works as a slave flash with the kit flash and with my C3 when using JJC hot shoe adapter (but live view is too dark, lets hope that Allacax flash trigger works). It is quite heavy and I am not so fond of flash on top of camera anyway. I will use it as slave flash until I will get the Allacax. I haven't tested the flash fully, I will put it into lightning stand and use umbrella next week. I think that it will provide enough light even if it's guide number is optimistic as Nex-C3 makes very nice pictures with ISO 400. Construction quality is ok outside but I don't know how well it is made inside. Price is something like 40 USD from Ebay.Advertisement It has a PC and external power sockets. External power socket is helpful it it takes high voltage as most of the heat generated comes from voltage step up system. External power packs cost probably much more than the flash. There is also a somewhat higher power unit, TT560. These are very useful as slave flashes with TTL camera flash too. Put something like 5 meters away from the TTL flash and using small power and a softener they will even out light very nicely. There is quite much information about that (Google strobist). I will construct some kind of light weight for them (sheet music stand?). I will probably get an another unit when I have more money (allacax, monopod, tripod, grip head, 5 lenses [latest was Vivitar Series 1 70-210/3.5 for 26.50 GBP] did take this and next month spending money).