SAFE SYNCS Safely reduces any electronic flash source from up to 400 volts to less than 6 volts to the camera sync input. This is absolutely mandatory for all high end and digital cameras. H prong or "household" connections from PC sockets to flashes is the most reliable type of connecter. The household connection never seems to accidentally disconnect . Instead of having multiple different PC cord types for all of your different flashes, convert all of your various flash connections to the household standard by employing this device and just a single household to pc male cord. The Wein HSH adapter has a hot shoe connections on top and a "cold" shoe upon the bottom, as well as a threaded 1/4"-20 socket so that you can attach the device to any 1/4"-20 threaded screw if you desire. The HSH provides a "H" household socket on the side of the adapter that allows you to connect accessories with a household type plug. As the Wein deliberately fits the flash's foot extremely tightly, this device is not intended for daily use with mutely-pin TTL flashes. It is okay to use with TTL flashes from time to time; just be careful and deliberate when attaching and removing the flash from this shoe. The benefit to these narrow tolerances is absolute reliability.