It looks like this Part has been superseded by LEGO Part 2350c Crane Arm Outside, New Wide with End Notch, 2 Fixed Rotatable Friction Pins.
Click on a colored part below to see the Sets and MOCs that use part 2350a Crane Arm Outside, Old Narrow 15 Studs On Top in that color. You can find an overview of all LEGO Colors here.
If a color is missing, it probably needs to be added to a Set Inventory.
There are 4 Mold variations of part 2350a - Crane Arm Outside, Old Narrow 15 Studs On Top in the database, in use between 1987 to 1992. See Molds and other related Parts.