RAM® Universal Marine Electronic Mount - B Size Short RAM-101AU-D Tighten the knob on the

Tighten the knob on the metal strap with a screwdriver until it has a firm hold on the rail

long double socket arm

The RAM-251-1SA is a 9" x 9" aluminum base withe the universal AMPS hole pattern

Both bases have the AMPS hole pattern

The 1" rubber ball is positioned at a right angle to the plane of the mount so when connected to a rail

RAM® Universal Marine Electronic Mount - B Size Short RAM-101AU-D Tighten the knob on theThe RAM B 111U A consists of a short double socket arm, 2. 5" diameter round base and 6. 25" x 2" rectangle base. The round base contains pre drilled holes, including the universal AMPS hole pattern. 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.