Replacement Clamp for 1/2" Base Swing Arm Lamps Simple clamp accommodates all swing arm lamps with (unwired) 1/2" stem. Clamp will attach to any horizontal surface up to 2 inches thick, and easy wing nut adjustment holds lamp securely in position. Layer of padding on clamp protects table, desk or shelf surface; patented unique design keeps lamp secure. Don't settle for a counterfeit! This replacement clamp is patented and produced exclusively for HOPE Hill Products. Rather than replace your entire lamp if the clamp fails, simply pick up this replacement clamp!