These are the same size and shapes of the keychain cubes but instead of a keychain these have rare earth magnets also known as neodymium magnets. Super strong and will adhere to any metal surface. Great gift ideas for loading benches or for someone who just wants something different other than just colorful letters on their refrigerator door. mostly all calibers from .380 up to 500 S&W can be made into magnets just like the keychains. Many styles to choose from. Buy more and save! Please contact for multiple discounts!