One of the hardest Boss pedals to get hold of...

Boss. Slow Gear SG1 Pedal. Black. Dimensions are 4 3/4" L x 2 3/4" W x 2" D. In original box.

Specifications:
Controls: Sens, Attack
Connectors: Input, Output, AC Adaptor
Current Draw: 4 mA (DC 9V)
Recommended AC Adaptor: ACA Series

Labels:
Black - Made In Japan

The SG-1 filters out the attack of your note, and swells the volume automatically. There are only 2 controls, one for the attack speed, and the other for sensitivity. The attack knob controls the speed of the volume swells. A compressor or overdrive in front of it may be helpful to minimize the variations in your signal level for the SG-1's response. Used with a delay it sounds sort of like a more articulated E-bow or a passage played backwards.

The SG-1 circuit is very similar to the NF-1. The pedal was in fact made using the exact same circuit as the NF-1 but the way it works is completely opposite. With the NF-1, the sound decays away but is cut when it falls below a threshold. With the SG-1, the attack is filtered out and then the sound increases gradually. The Slow Gear is a rather unique effect and the SG-1 has become one of the hardest Boss pedals to get hold of. Expect to pay top money if you find one.