RAM® Universal Marine Electronic Mount with Diamond Base 400 31" diamond base with 2

31" diamond base with 2 hole AMPS pattern and a strap clamp base for rails between 2" and 3" diameter

One of those round plates has a 1/4"-20 male threaded post in the center

At a fraction of the cost of traditional key locking knobs

The RAM-247U-4NH is a clamp base with 1

double socket arm and 7" x 14" mirror

RAM® Universal Marine Electronic Mount with Diamond Base 400 31" diamond base with 2The RAM B 111 238U consists of a double socket arm, 2. 43" x 1. 31" diamond base and 6. 25" x 2" rectangle base. The diamond base contains two holes 1. 912" from center to center, positioned at both ends of the base. The rectangle base contains different combinations of pre drilled holes which will match up to many electronic devices and mounts, including Marine GPS, CB Radios, Ham Radios, Gimbal Brackets and more.