I just received a package of FlashQ syncs. One transmitter, two receivers for USD $55 plus $6 shipping. They are tiny at 25mm square and with the three stacked are 62.7mm. Turned them, sync'd them with each other, mounted and used them, all the way up to 1/320 on my E-M5 and FL-600R flashes. I took them off and put them back on and only sync'd at 1/250, took them off, put them back on and back to 1/320th sync. I'll be ordering another kit.