Option: 3.5 inch is just that a cup holder with a diameter of that. Option: Yeti 30oz Rambler was made specifically for that tumbler & has a diameter of 86mm / 3.38 inch. Option: Custom size, for any other sizes you may want or need, just message me some dimensions & ill modify it to you. Option: Rockstar/Redbull, will fit Rockstar sized cans(soda). Has an insert that you flip upside down to use it for a Redbull sized can. Can be mounted on the left or right side & will clear the side handles. you will also receive 2 self tap screws to mount it. Ships free Via First class mail Milwaukee Packout Cup Holder | Yeti 30Oz, 3.5In, Or Custom Size