Someone had sprayed these with turquoise-blue paint, then with a faint dusting of dark gray, then with a dull topcoat. Each one lay in its own blur of overspray. The three aerosol cans stood in a row at one end of the plywood. Putting on latex gloves, Garreth carefully picked one up, exposing the perfect round of unsprayed plywood beneath. He showed Tito its unpainted back, bright silver metal. "Rare-earth magnets," he said, "painted to match the box as closely as possible." He indicated two printouts, photographs of a shipping container, a dirty turquoise blue. "Once you place one on a flat steel surface, it’s difficult to remove, except with a knife or a thin screwdriver blade. We have ten, but you’ll have a maximum of nine holes to cover. The spare is in case you drop one, but try not to."