Neewer Aluminium Alloy 2.5 lbs/1.1 kg Counter Weight for Balancing Shoulder Rig Mount Stabilizer Fits 15mm Rods Specially designed for balancing your shoulder mount rig, to regain the feeling of sturdiness, stability, and sureness for your growing heavier rig This product weighs 2.5 lbs/1.1 kg. We use high quality aluminium alloy to boost stability for this product Three steps, several minutes, fast and simple way to balance your shoulder mount rig It fits 15mm industrial standard rods, making it versatile on industrial standard shoulder mount rig If one counterweight is not enough,a 1/4"-20 thread in the center of the counterweight enables you use a screw to put on another one!(Note:you need to buy the screw additionally)