fill n brew insulated mug, plastic, 16 ounces lami products inc a flimsy styrofoam cup of coffee in the car is not a great idea. the lid can pop off if you grab the cup too tight and then coffee goes everywhere. you end up getting burned with hot coffee all over your clothes and car seat. time to switch cups. this cup is easy to fill, slides open with a convenient lid, and the lid fits snug into the cup. easy to hold open handle with ergonomic cup fits most car cup holders. bottom of cup has skid proof surface. this cup is great for tea, coffee, hot cocoa, broth and more.