(PS500-2) PRO-SYNC 2-CHANNEL SYSTEM has "H" Prong(plus PC) style receiver(W928210). TWO-CHANNEL TRANSMITTER (W918112)Color-coded On/Off switch. Battery saver circuit provides 5000 firings from two AA alkaline cells. Ready light, open flash test button. Locking shoe mount; triggers by hot shoe or via PC cord (supplied). 2-1/2 x 3 x 1-1/2". 3 oz (less batteries). Supplied with:10" Miniplug-to-PC coiled cord for non-hot shoe cameras. Universal stainless steel mount clip. Extra Velcro strip.Batteries:Requires two AA alkaline for transmitter (not supplied)