The RAM^® Mounts Universal Heavy Duty Marine Electronic Mount with 2.25" Ball and RAM^® Hi-Torq™ Wrench is designed for a variety of electronic devices, including large fishfinders such as the Lowrance HDS-16 Carbon, CB radios and ham radios, gimbal brackets and more. The 2.25" ball and socket system system features an 11" x 3" rectangular plate with different combinations of pre-drilled holes to securely seat your device, and a round 3.68" diameter flat surface base. Use the RAM^® Hi-Torq™ Wrench on the knob to give the arm an extra tight hold. Ball 2-1/4" Length 8.25"