RAM Part number RAM-109HSB : The RAM single swing and socket arm mount includes a 6" STRAIGHT swing arm mounted on a horizontal surface mounting base. At the end of the mount is a rectangular 6.25" x 2" top base. The pivoting point of the rectangle base allows 180 degree rotation, the swing arm allows a 360 degree rotation.  Constructed of powder coated marine grade metal.

These fit many models including:
Lowrance LCX-104C LCX-110C LCX-111C LCX-112C LCX-113C Fishfinder
Lowrance LCX-17M LCX-19C LCX-20C LCX-25C LCX-26C Fishfinder
Lowrance LMS-332C LMS-334C iGPS Fishfinder
Lowrance HDS-5 HDS-5M HDS-7 HDS-7M HDS-8 HDS-8M Chartplotter
Lowrance Elite-7, Elite-7m, Elite-7x
GARMIN FISHFINDER 320C
GARMIN GPSMAP 180
GARMIN GPSMAP 182
GARMIN GPSMAP 182C
GARMIN GPSMAP 185 SOUNDER
GARMIN GPSMAP 188 SOUNDER
GARMIN GPSMAP 188C SOUNDER
GARMIN GPSMAP 192C
GARMIN GPSMAP 198C SOUNDER
Compatible Makes & Models
GARMIN GPSMAP 2106
GARMIN GPSMAP 2206
GARMIN GPSMAP 230
GARMIN GPSMAP 232
GARMIN GPSMAP 235 SOUNDER
GARMIN GPSMAP 238 SOUNDER
GARMIN GPSMAP 3005C
GARMIN GPSMAP 3006C
GARMIN GPSMAP 3205
Compatible Makes & Models
GARMIN GPSMAP 3206
LOWRANCE LCX-104C
LOWRANCE LCX-110C
LOWRANCE LCX-17M
LOWRANCE LCX-19C
LOWRANCE LCX-20C
LOWRANCE LCX-25C
LOWRANCE LCX-26C HD
LOWRANCE LMS-332C
HUMMINBIRD 947C 3D COMBO
HUMMINBIRD 931C
HUMMINBIRD 937C COMBO
HUMMINBIRD 981C SI
HUMMINBIRD 987C SI COMBO
HUMMINBIRD MATRIX 97

Dimensions:
A. Center of knob to center of ball socket: 6"
B. Overall length of swing arm assembly: 10.75"
C. Height from base to top of knob: 4.89"