Use for repairing small holes, rips or voids between panels. The 90 degree angle 100% Copper “spoon” supports your welding from behind. The handheld 90-degree angle is designed for corners, seams, rails, channels and more, plus you can change the position the angle for an outside or inside weld. The sppon acts as a heat sink to prevent warpage. The special mounting design permits setting the back offset left, right, and straight. Made in USA