Our Closeable Press-In Lids slide shut to tame splashes and trap temps, then slide open wide enough for easy drinking and reusable straws. Size small compatible with 6 oz Mug, 10 oz Wine Tumbler, 12 oz Cooler Cup, Tandem Cooler Cup, 16 oz Tallboy Cooler Cup, and 12 oz All Around Tumbler. Tames beverage splashes and keeps heat and cold from escaping. Easily presses into compatible products. Slides open wide enough for easy drinking and reusable straws. BPA-Free & Toxin-Free. Dishwasher safe, or hand wash with warm, soapy water. Rinse well. Avoid cleansers with bleach or chlorine. Wash before first use. Not for use on a stove, in a microwave or freezer.