The SRT101 can use flash bulbs and electronic flash units. There are two sync terminals on the camera marked "X" and "FP". When using an electronic flash, set the shutter to at 1/60 (red figure on dial) and use the "X" terminal. When using "FP" class bulbs, you can use any shutter speed from 1 to 1/1000 as the flash bulbs sync with the release of the shutter.
The only thing you need to know about the electronic flash is that it has a standard foot and a PC cord to connect it. A flash with conventional "auto" settings will be more convenient than a manual-only flash.
Almost any flash you can find will meet these requirements.... the exceptions are special dedicated flashes made for a particular camera (particularly in the autofocus era), and some 'hot shoe only' models that don't have the cord.
