Ram Mount Universal D Size Ball Mount with Long Arm for 9"-12" Fishfinders and Chartplotters [RAM-D-115-E]Universal D Size Ball Mount with Long Arm for 9" 12" Fishfinders and Chartplotters The RAM D 115 E consists of a base with a 2. 25 diameter D size ball, a long arm and a 6. 25 x 2 marine electronic plate with a D size ball for supporting larger devices. This marine electronic plate contains different combinations of pre drilled holes and is a direct fit for 9 12 fishfinder gimbal brackets. Supports devices such as the Lowrance HDS 9 Gen2 Touch, Garmin