Retro Style Mermaid Shell Party Favors. Plastic clamshell in purple iridescent. Reminiscent of the 90s look and style. Perfect for an Under the Sea, Ocean, Nautical, or Mermaid themed pool party. Purple Iridescent Seashell Party Favor Containers Set of 10 Purple Iridescent Plastic Clamshell Containers These are not the best quality, some were hard to close or came apart when you opened them but they are gorgeous to look at! Can hold Jewelry, Candy, Medicine, etc.