Lab Support Stands and Rings Lab Support Stands and Rings Lab Support Stands with Rods - Available in Stamped Steel with Black enamel finish or Heavy cast iron bases with black enamel finish / Removable zinc plated steel rods. Small Support Stand: Base: 4 x 6 Rod Length: 18" Rod Diameter: 5/16" Medium Support Stand: Base: 5 x 8 Rod Length: 20" Rod Diameter: 3/8" Large Support Stand: Base: 6 x 9 Rod Length: 24" Rod Diameter: 1/2" Extra Large Support Stand: Base: 6 x 11 Rod Length: 36" Rod Diameter: 1/2" Lab Support Rings, Cast Iron Available in Diameters: 2", 3", 4", 5", 6", and 7" Zinc plated cast iron support rings with integral support clamps for attaching to support rods from 5/16" to 5/8" in diameter. Support rings for supporting beakers and flasks on a ring stand. Please click to view our entire line of Laboratory Glass Beakers, Erlenmeyer Flasks, Filtering Vacuum Flasks, Boiling Flasks, and Glass Cylinders.