Please note: Price is for one Magnetic Copper Welding Backer Eastwood’s 4-long Magnetic Copper Backer helps you weld without burning holes. It provides a hands-free support when doing butt-welding or welding holes in sheet or whenever an open area needs to be bridged with a weld. Prevents warping and weld burn-thru. Because the Eastwood Welding Backer is magnetic, no hands or clamps are needed and your welding material won\'t stick to the copper. 1/8-thick solid copper, with high-strength, high-heat magnets