The Cup hole diameter is 3.5 inches. Specially designed for large drink cups. Each foldable cup carrier is designed to fit different sized cups ranging from 20 oz to 32 oz, which secure your drinks in place and prevent spills The Foldable Plastic Cup Holder is made of high-quality PP plastic, durable and lightweight. It really helps to keep drinks standing during deliveries when you go over speed bumps, or take a corner Fast open and fold design allows it to hold the cup/bottle easily and fold flat for storage. When not in use, a portable cup carrier with a handle easily folds up flat for simple and convenient storage