20PC 11KG Neodymium Steel Shell Magnet Pot D20*7mm Through-hole 4.0/8.0mm Rare Earth Speaker Precision Machine Fixture

1.Silver Color 2. 20pcs as a lot. 3. Each with through hole 4.0/8.0mm . 4. Made of N42 neodymium magnet and steel shell, the magnet is putted into one steel shell which concentrates the magnetic force on one side of magnet and increase the attracting force of magnet incredibly (2.5-4 times for same size of magnet) . Meanwhile, the steel shell protect the neodymium magnet against chipping and cracking. 5.Mainly used for precision machines , Led panel, mini signal led lighting etc.