Screw-in slave flashes need this Smith-Victor ULM45 Umbrella and Light Mount . It features a standard Edison base thread socket with an 120V AC power line, a swivel for light angle adjustment, a receiver to mount an umbrella, and a 5/8" diameter receiver for fitting it to the top of a light stand. Besides slave flash the ULM-45 can be used for photofloods up to 500W.
In the Box
Smith-Victor ULM45 Umbrella and Light Mount (120V AC)