An innovative approach for locating hidden holes that's a more practical and accurate solution than strap duplicators or transfer pins when working in confined areas or with unusual shapes. It utilizes a combination of tiny magnets and a sheet of green magnetic field viewing film to see where hidden holes lie. Use it by taping a magnet into each of the holes of the underlying sheet, then secure the overlapping sheet in place with clamps or clecos. You then scan the surface of the overlapping sheet using the viewing film. When the film is over a magnet, it will darken indicating the presence of the magnet, and of course the hole. Once you locate the underlying hole, use a center punch to mark the overlapping sheet for drilling. 1 lbs (0.5Kg) shipping weight.