Very good condition. No issues. Photos are representative of overall condition. Includes original box, manual, and power supply. 
From Boss:
DescriptionThe MS-3 Multi Effects Switcher is a new-concept pedalboard solution that maximizes your creative options by combining a world-class multi-effects engine and multi-pedal switcher in one small, dedicated unit. Now, anyone can put together a professional effects system that's incredibly compact, extremely light, and versatile enough to achieve nearly any sound imaginable.

The MS-3 is capable of running six internal pedal effects at once while seamlessly integrating three of your favourite external pedals. It also offers deep rig control capabilities, allowing you to switch amp channels, adjust effects in real time, work with MIDI devices, and more.

With the MS-3, it's easy to create a portable board or fly rig without the compromises associated with traditional loop switchers and all-in-one multi-effects units.

Specifications:

Modes: Memory mode/Manual mode
Loops: 3
AD/DA Conversion: 24 bits
Sampling Frequency: 44.1 kHz
Effects: 112 types
Patches: 200
Connectors:
- INPUT jack: 1/4-inch phone type
- LOOPS L1--3 SEND jacks: 1/4-inch phone type
- LOOPS L1--3 RETURN jacks: 1/4-inch phone type
- OUTPUT (L/MONO, R) jacks: 1/4-inch phone type
- CTL OUT CTL1/2 jack: 1/4-inch TRS phone type
- CTL IN EXP1 CTL1/2 jack, CTL IN EXP2 CTL3/4 jack: 1/4-inch TRS phone type
- USB COMPUTER port: USB type B
- MIDI OUT connector
- DC IN jack
Power Supply: AC adaptor
Current Draw: 280 mA
Included Accessories: AC adaptor, Rubber feet x 4
Dimensions (W x D x H): 246 x 97 x 68 mm (9-11/16 x 3-7/8 x 2-11/16 inches)
Weight: 1.1 kg (2 lbs 7 oz)