Paramount has been supplying highest-quality sync cords to the professional photographic community for over 50 years. It is the only company in the history of photography dedicated to providing a "better sync cord". Half a century of experience and thought goes into every Paramount product. No single cord leaves the factory without undergoing intensive inspection and testing.The "Sync Cord", your only link between camera and flash, is essential to your success. If it fails during a shoot, it can destroy the job along with your reputation! The sync cord is a vital piece of equipment, not to be taken for granted. Why risk connecting a high-end camera to a professional flash with an unreliable or inferior cord?The 1-1S is a Household to Bipost.The Bipost fits older Speed Graphic cameras, Crown Graphic, Wollensak Lenses, Rodenstock Lenses, Camerez and Photo Control cameras. Identified by two pin contacts protruding from the lens about 1/4 inch apart.The Household (HH) fits most professional flashes with dual blade receptacle, such as Lumedyne, Norman, Braun and Dynalite. Units with 3-prong plug can also use this plug. Examples of the 3-prong plug are Dynalite (3 flat blades), Sunpak and Quantum Radio 4i (2 flat blades with 1 round blade in center). Third prongs prevent plugging these cords into wall sockets!