AW 3Pcs Professional Photo Studio Tripod Swivel Caster Wheel for Light Stands & Studio Boom 3" Wheel in 3" diameter, easy and smooth rolling Weight: only 2.8lbs each, lightweight and durable Heavy duty construction for light stand, tripod With an adjust screw to fit most light stands With a stator to fit 3/4"(16-22mm) light stand steadily