Powerful Alnico 1 Grade Bar Magnets, Shipped In Pairs, With End Keepers. Magnets Are Painted With North And South Poles, Clearly Marked. Width 1/2", Thickness 1/4". Powerful Alnico 1 grade bar magnets, shipped in pairs, with end keepers. Magnets are painted with North and South poles, clearly marked. Width 1/2", Thickness 1/4".