These adorable heart shaped locks are made of metal. They are the perfect size to add to a stem of a flower, put in a gift bow, put into an envelope with a greeting card, add to your keychain - as well as so many other things!!! They actually open with the key provided. The size is about 1 1/4" x 1 1/2". The perfect add on impulse item. They are shipped in sets of 20 - 5 colors (4 each of - gold, blackish, silver, pink and red)