Wilton Spark-Duty 400 Series Hi-Vis C-Clamps are ideal for steel fabrication and industrial welding. Each boast a drop forged construction, an ACME rolled, copper plated spindle and conform to OSHA safety color standards for physical hazards regulation# 1910.144. Each has an oscillating head with a high quality steel pad built to last and provides firm gripping action on angular surfaces. This kit includes four of our most popular sizes ' H402CS C-Clamp 0 - 2" Opening Capacity, H404CS C-Clamp 0 - 4" Opening Capacity, H406 CS C-Clamp 0 - 6" Opening Capacity and H408CS C-Clamp 0 - 8" Opening Capacity.