Description Our cup holder inserts suitable for boat, RV, or cars with 3.74"-4.1" cup base (Please measure the diameter in advance before you make the purchase). cup holder inserts also can perfect replacement couch cup holder. The cup holder can perfectly hold your Hydro Flasks Nalgenes Yeti Ramblers Klean Kanteens or other large bottles. Dimensions of the cup drink adapter: cup base of 3.74"-4.1" in diameters and fits cups of up to 3.6" in diameters. To prevent you from buying by mistake, please be sure to confirm the size before buying The package includes 2 pieces of cup holders, which can be installed such as couch, table, sofa, golf cart, dashboard, chair, seatback, furniture, etc. If you have any questions about our drink holder insert, please feel free to contacts us. We will give you a satisfactory solution. Important Please make sure the cup base in your car or boat has a diameter of 3.74"-4.1" so our recessed cup holder can fit properly. The cup holders with 3.62" opening compatible with Hydro Flasks 12oz/16oz/18oz/20oz compatible with Yeti Ramblers 20oz/26oz/30oz compatible with Nalgenes 30oz compatible with Cola can 12oz among other big and small size cups.