IDEAL FOR DISPLAYS. These discreet, ferrite hook magnets are great value for money and ideal for hanging signs and decorations from a steel ceiling and are commonly used in shops to suspend advertising signs. STRONG MAGNETIC HOLD. Each magnet can support a steel weight of up to 10.2kg vertically from the magnetic face when in flush contact with a mild steel surface of equal thickness. SPECIFICATIONS. 40mm diameter x 34mm high. The internal diameter of the hook is 4mm and is 18mm from the tip of its thread to top. PREMIUM FINISH. Black powder coated finish.