Eclipse Magnetics E634 Round Magnetic Tray, 4.3" Diameter Stainless steel trays with rubber coated ferrite (ceramic) magnets in the base 5.9" Diameter Magnetshold the tray to any magnetic surface without marking it or any ferrous components in the tray Trays canhold non-magnetic articles too Magnet base is rubber coated to safeguard surfaces Neodymium (rare earth) magnet, uncoated - N38SH Grade (Higher temperature grade than N35) Neodymium magnets are the strongest magnets available Pull force of 10.7 pounds Maximum temperature of 145 degrees C 0.5-inch length x 0.5-inch width x 0.25-inch thickness, bare