Foto4easy U Type Clamp Clip Bracket with 1/4" Copper Screw Mount for Boom Arm Light Stand High High Quality Construction, With an Emphasis on Strength Can be used to hold small strobes, continuous lights, slaves which you may need to clamp Help make better use of the Stands you have Can also be taken as a Backup when light Stand is Not available Screw Thread Diameter: 1/4" 5/8" copper stud for mounting accessories