The Manfrotto Ezybox II Elinchrom Quadra Spigot allows you to mount the small, lightweight A or S designation Quadra heads on an Ezybox II Speedlight Bracket so it can be used with an EzyBox softbox. The metal spigot has a 5/8" (16 mm) diameter and a 1/4"-20 screw at one end and a 3/8"-16 screw at the other. A separate knurled locking knob is also included to secure the head.