Gadjit Cup Keeper 2-Pack (Black) Car Cup Holder Adapter Expands Cup Holders to Hold Mugs, Convenience Store Cups, Water + Soda Bottles with up to 3.6" diameter, Fits Yeti Rambler 20 oz 30 oz When you're in the car, wouldn't it be nice to have a cup holder that would actually hold your coffee mug, over-sized soda cup, or favorite water bottle? Allows a mug, cup, or bottle fit in your vehicle's standard cup holder. Fits Most Cars No installation needed. Just place in standard cup holder. Dimensions: 3.6" diameter top of cup, 3.375" diameter bottom of cup. Portable -- move from one vehicle to the next.