6 of 1/2" x 1/4" with 1/8" Countersunk Hole Strong Ring Magnets 4Kg PULL Magnet
SizeD1/2" x 1/4" with 1/8" countersunk Hole +/- 0.1mm. 4Kg (4000g). Usually surprise is an issue--they can jump out of your hands and snap together from a surprising distance before you realize what is happening.