Use for repairing small holes, rips or voids between flat, round and angeled panels. The 3 by 3 Set of 100% Copper “spoons” supports your welding from behind. The sppon acts as a heat sink to prevent warpage. The special mounting design permits setting the back offset left, right, and straight. Set includes an Offset Flat Plate, 3.5″ Radius Curve Plate and 90 degree angle plates with two set screws and handle. Made in USA.