This is a collapsible stainless steel folding cup with 3 layers. It is made from premium food-grade 304 stainless steel for durable use. It's electro-polished for added rust protection, recyclable, super strong, and dishwasher safe. It is widely used as a shot glass for a cup of beverage for any outdoor or indoor occasions. It comes with a key ring, fitting in the palm of your hand, slipping into your pocket or attaching to your keys on your travels.