These are very powerful "rare-earth" permanent magnets. Very small and highly effective! Contains:

• 4 high-quality Nickel-plated NdFeB (Neodymium-Iron-Boron) disc magnets measuring 3/8" diameter x 1/16" thickness
• 4 very high grade (N45) Gold-plated disc magnets measuring 1/8" diameter X 1/16" thickness

(Pennies in the photo are shown only to give perspective on size...they are not included)

This item does not come with instructions.