The base of this mount expands out to 3 3/4 inches in diameter by turning the adjusting knob. The neck of the mount is flexible so you can adjust the mount for the perfect view of your device. The mount comes with the LM-801-EXP-1. The LM-801EXP has a 4 hole amps patern which will match the 4 holes in the metal plate in the MBA-2 if you have an ID-5100 or the MBA-5 if you have the IC-2730.
Please note the Icom remote head brackets, MBA-2 or MBA-5 are not included. You will need to purchase them from an Icom dealer.