Set of 20 magnets 3/8" long x 3/8" wide x 1/8" thick (9.5 mm x 9.5 mm x 3.2 mm) Material: Neodymium (NdFeB) Grade: N48 Coating: Nickel (Ni) Magnetization: Through Thickness Pull Force: 5.2 pounds SKU# M38x38x18BL NEODYMIUM MAGNETS ARE NOT SAFE FOR CHILDREN