Dimmer assembly, brass, watertight, 20 amp output, 0-120 VAC 60 Hz input, 0 - 140 VAC 60 Hz output. This Type W-20 autotransformer is mounted within an 8 x 10 x 5 brass enclosure per MIL-E-24142/6. The large plastic knob controls the output voltage in conjunction with the circular dial plate mounted on the cover. To minimize the corrosion effects commonly experienced by other designs, we connect the operating knob to the shaft of the autotransformer by a coupler with a shaft seal to maintain the watertight integrity and which permits the easy removal of the cover under any conditions for servicing or repair. Connections are made directly to the terminals on the autotransformer which are located on one end of the unit. The autotransformer is positioned as far to the opposite end of the enclosure as possible to provide the maximum area for cable entry, connection, and servicing. NSN 5905-01-605-1569 is assigned to this item. Please order by part number 404234-102 and description. This item is Grade A HI shock per MIL-S-901D and vibration qualified per MIL-STD-167.