CameraPlus - Heavy-duty Multi-purpose Studio Clamp Ideal clamp for photographic application. Ergonomic lever to securely lock clamping position. Opening Dimension: can take round tube of 50mm maximum, or square tube of 30mm thick maximum Maximum load is about 10KG. This heavy-duty, multi-purpose clamp can be used to attach light heads to stands, pipes or anything up to 2 1/4" diameter. It features a 5/8" stud and will accept a wide variety of accessories that extend the uses of this indispensible tool immensely. Reserved multiple function extension holes, including 1 x 5/8" hexagon hole, 1 x 1/4" UNC hole and 2 x M5 thread holes Main body die-cast of aluminum alloy, surface grinded and polished, tapped and drilled, painted with high temperature. with an alloy spanner, stainless steel spring, zinc plated pin button and copper nut, strong and durable