Futaba FUAS4139 Replacement Servo Case for S3153-size Servos  [FUAS4139]

Overview and fitment guidance

The Futaba FUAS4139 case is provided as a replacement housing to mount S3153-size servos within scale models and similar applications. It is supplied without retail packing and is intended to secure the servo body while allowing accurate alignment with the model structure.

Compatibility is focused on servos that match the S3153 external dimensions and other units with equivalent outer form. The case offers a stable mechanical enclosure to retain mounting alignment and to hold the servo steady during tuning and use. This product does not include any servo electronics.

Fitment advice: position the servo so the output spline and shaft remain free, confirm clearance around the horn and linkages, and use the existing mounting screws and spacers from your model where suitable. The case helps maintain consistent positioning when replacing or bench-testing servos.