Set of 2 magnets 10mm long 10mm wide x 10mm thick (0.4" x 0.4" x 0.4") Material: Neodymium (NdFeB) Grade: N48 Coating: WHITE HARD PLASTIC COATING Magnetization:Through Thickness SKU# M10mmCUPC Please note: these magnets were 10mm BEFORE the coating was applied. The finished product is .6mm thicker. Why are these 10mm PLASTIC Coated neodymium magnets so expensive? One of the biggest drawbacks to Neodymium magnets is though very strong, they are very fragile. Tough coatings, such as nickel, go a long way toward protecting the magnets from cracks and breakage. However, after repeated impacts with each other or other surfaces, even the best metal coatings will fail. One possible solution to the breakage problem is presented here. Each of these 10mm magnets is coated in standard nickel. Then, a special plastic layer is applied. This impact resistant coating offers a long lasting solution to high stress environments. If you plan to play with neodymium magnets A LOT - these are the magnets for you! NEODYMIUM MAGNETS ARE NOT SAFE FOR CHILDREN.