Soligor 14-S Flash unit

Cleaning out some old boxes, I found a box with a bunch of photography odds and ends - a bunch of Cokin A filters, a dozen or so round filters (all too small for any of my current lenses...not that any would be very useful on digital...), a 50 foot pneumatic shutter release, and a film leader retriever, and a couple flashes from my K1000 days...

I was wondering if anyone could tell me anything about the flashes... I got them 30 years ago from a junk bin in a Toronto camera store for a couple bucks each... They are Soligor 14 S flashes, and I'm guessing the S is for Slave, and that's all I ever used them for - they have a sensor that sets them off when they 'see' another flash... They do have a hotshoe, but I never ever used them that way, and probably shouldn't on my K10D...

I used to shoot a lot of photos of groups of people back then, not paid portraits or anything, mostly yearbook style shots... I'd position the group about 8 or 10 feet from a neutral coloured wall, lay the 14S on the floor behind the group facing straight up, and it would both light the background (hiding any shadows my on-camera flash created) and provide a bit of a backlit effect, that sometimes looked good, and at worst wasn't strong enough to detract from the picture.

Does anyone have any info - GN rating is what I'm looking for... I'll find my multimeter and check the voltage...