This is a collection of several different designs and manufacturers of the Old type sockets with Ceramic screw on bulb holders . Some have the Bayonet type socket . Bag of extra pieces . These are from a Lighting Manufacturer who kept them after restoring and converting old Lamps and Chandeliers to the American Standard sockets . They are very hard to find if you need any now . Most were thrown away .  Selling as a Lot !