Vintage metal button covers silver clip closures southwestern heart set

Bought before 1980s and each is about 3/4”wide except for the oval one which is about 3/4”long x 1/2”wide. Unsure if these are pure silver or plated. There are 6pieces in the set. How to use these - Flip the cover open like in the picture and slide it into an existing button (smaller than this cover) and clamp it down thus holding onto the button. This gives a different look to an existing button down coat or top. Thanks for browsing. All sales are final. impeccable for everyday use. premium materials and excellent craftsmanship ensure long-lasting durability.​