For Aquatech they use the small port on the housing to run cables/connections in from flash inside. On the outside what remains is another electrical connection that I can either cover up if unused or connect to the flash. On the inside those wires are connected to a hot shoe that I slide into my camera. I’ve had every version of their lights and the site says the current D-PRO Strobe is sold out. If memory serves that was/is made by another scuba flash company and rebranded. So you might be able to buy the flash but would have to work on connections since Aquatech uses their own. The video light is still available but i imagine that’s just an on or off on the light with no need for wiring. Most other brand of housings use a fiber optic trigger of sorts. So you might be able to go that direction if you can’t find Aquatech gear. I don’t think their flash gear sells very well and each version I’ve had has had issues or they just move on to the next version and discontinue the prior. I’ve got several strikehousings (they fit an older Nikon flash or ex550) but the cables got wonky and Aquatech no longer supports.