These are for a dog lover in your life. These are 12mm x 9mm. They are jewelry grade stainless steel with the colour anodized on top. They are non tarnish, non corrosive, no fading and can be worn in water, whether shower, hot tub, pool, or ocean. They are hypoallergenic and even non allergenic for most people. They contain no lead or nickel (the most common allergen). They have a butterfly back. This lovely puppy has a open heart and is ready to be part of your everyday life.