I use these on three Vivitar 285HVs for portrait and product shots. The PC plug works great in the "Proprietary" 285's plug on the side of the Flash's base. I've found though that a small piece of two-way foam tape between the base of the peanut slave and the Vivitar base keeps the peanut slave nice and snug sos that it won't fall out. I dropped one from about waist high onto a concrete floor, while it didn't appear damaged, it did stop working. But generally they're pretty reliable.