Keep Hot: Keweilian Silicone Cup Covers are ideal for keeping your tea at the perfect sipping temperature while you attend to other things. | Material: high quality food grade silicone, environmental protection, safety, non-toxic. | Keweilian Silicone Cup Covers Fits Most Cups & Mugs (3.94 INCH DIAMETER): Our Silicone Mug Covers are perfectly designed to keep your delicious beverage. | High Temperature Resistant: -40~230 F,Silicone can handle extreme temperatures,safe. | Health: Protect your precious drink from dust.