Check the listing for details. 20mm x 10mm x 1mm N52 Thin Strong Rare Earth Neodymium Magnet Block 20x10x1mm. Condition: New. Listed at 14.50 USD. 20mm x 10mm x 1mm N52 Thin Super Strong Rare Earth Crafts Fridge Magnet Blocks Specification:Dimensions: 20mm x 10mm x 1mm thick Tolerances: ±0.1mm x ±0.1mm Plating/Coating: Ni-Cu-Ni (Nickel) Magnetization Direction: Axial (Poles on Flat Ends) Max Operating Temp: 176ºF (80ºC) Pull Force: approx. 2.65 LB Material Features:Magnets are made of a brittle material. These magnets are not as strong as steel. They are more like a brittle ceramic. If you let two magnets slam together, they can crack and break. This is true for magnets large and small. WARNING!!! Strong magnets should Keep away from Ironware and some easily magnetized iron products, such as monitors, bank cards, computers, televisions, mobile phones and other. These magnets are very powerful which should be handled with great care. Without parents supervised do not allow children to playing magnets as they could get injured. Especially pay attention to the small magnets, please place in somewhere children can't reach place.20mm x 10mm x 1mm N52 Thin Super Strong Rare Earth Crafts Fridge Magnet Blocks Specification:Dimensions: 20mm x 10mm x 1mm thick Tolerances: ±0.1mm x ±0.1mm Plating/Coating: Ni-Cu-Ni (Nickel) Magnetization Direction: Axial (Poles on Flat Ends) Max Operating Temp: 176ºF (80ºC) Pull Force: approx. 2.65 LB Material Features:Magnets are made of a brittle material. These magnets are not as strong as steel. They are more like a brittle ceramic. If you let two magnets slam together, they can crack and break. This is true for magnets large and small. WARNING!!! Strong magnets should Keep away from Ironware and some easily magnetized iron products, such as monitors, bank cards, computers, televisions, mobile phones and other. These magnets are very powerful which should be handled with great care. Without parents supervised do not allow children to playing magnets as they could get injured. Especially pay attention to the small magnets, please place in somewhere children can't reach place.