This RAM Mount Finger-Grip Cradle has a diamond base adapter which attaches to the 3" double socket arm. Made out of high a strength composite material and can be adjusted to accommodate a wide range of phones and GPS devices. The Finger Grip can be adjusted to fit anything from an iPod Nano to a Samsung Galaxy Note smart phone. 1" rubber ball and socket size Pair it with the RAM base mount of your choice and you'll be ready to hit the open road Here are a just a few bases that we recommend for your motorcycle: RAM Small Tough-Claw 753-334, RAM Torque Mount 753-930 or 753-929, or the RAM Mount motorcycle brake/clutch perch adapter 753-332