The thread of your mirror as a starting point for your RAM mounting? Then you need this item! Motorcycle base 9mm hole with 1'' ball.
Features a 9mm hole designed to attach to the mirror frame of motorcycles. Included B size 1" RAM rubber ball allows for connection to any B size RAM double socket arm; ball and socket technology allows for near-infinite adjustability. Made of powder-coated, marine-grade aluminium for durability and reliability in the most demanding environments.