All metal construction to carry heavy loads and prevent torque damage StonyLab 2-Pack Adjustable Bosshead Clamp Holder, Lab Heavy Duty Boss Eisco Labs Lab Equipment Clamp Eisco Labs Boss Head Clamp, Die Cast Alloy, Up To 16mm Rods Eisco Boss Clamps Thicker than normal 7 mm threaded clamping screws. Thicker casting to support more load. Accepts up to 16 mm rods. Made of high strength powder coated alloy. All metal constructions to carry heavy loads and prevent torque damage Holds rods orthogonal (90 degrees) to one another CH0663C Boss Head Rod Clamp, for Rods up to 5/8" (16mm) diameter, Painted, Metal Handles This series of boss head rod clamps are perfect for various lab and home uses Able to hold rods up to 16 mm in diameter