Made of quality silicone material, with no odor, soft to cups and safe to drinks, reusable and durable. Diameter 10.5cm/2.6",suitable for cups with a opening diameter of less than 10cm. could cover most of coffee cups, glass cups or mugs These silicone lids keep dust/ fur/ fruit flies out of your cup, don't worry about nasty bugs entering the cup after it's been sitting there for a while, so you can drink it safely.