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. Measuring 4.5oz, this custom 4.5oz collapsible stainless steel cup with keyring. Usage Scenarios: Office supplies, school stationery, corporate promotions, trade show giveaways. We offer logo printing and full packaging customization. Product Highlights: BPA-free, leak-proof, travel-friendly.