This NOS DR-3 is a great and affordable drum machine from Boss that features 100 preset styles, 100 user slots, 12-note polyphony, stereo main and headphone outputs, and the option to run on batteries (6AA) or to be powered by the included power adaptor. This piece comes with its original box and packaging that's a little worn with age.

Here's some more info from the fine folks at Boss:

With the DR-3 Dr. Rhythm, guitarists and songwriters can add incredible-sounding drums to their music. This ultra-affordable drum machine includes some of BOSS’ best acoustic and electronic drum kits and a selection of bass sounds. Great for jamming, the DR-3’s Rhythm Progressions and multiple variations make it easy to create a realistic-sounding drum track for any style of music. And with Total Sound Control, you can tweak your kits to perfection.

Technical Specifications:

Styles: User Style: 100, Preset Style: 100 * 11 patterns for a style

Songs: User: 100, Song Length: Max. 250 patterns for a song

TSC (Total Sound Control): Preset Patch: 8, User Patch: 8 Preset Patch: 8, User Patch: 8

Max. Polyphony: 12 voices

Instrument: Drum and perc: 120, Bass: 12

Resolution: 96 per quater note

Tempo: 20 to 260 bpm

Recording Method: Realtime/Step

Pads: 13 (Velocity-sensitive)

Display: Backlit LCD (16 characters x 2 lines)

Connectors: Output Jack: L, R (RCA Phono type), L(PHONES), R(MONO) (1/4-inch phone type), Foot Switch Jack (Stereo 1/4-inch phone type), MIDI IN Connector, DC IN (AC Adaptor Jack)

Power Supply: DC9V: Dry Battery (R6/LR6 (AA) type) x 6, AC Adaptor (PSA-series)

Power Consumption: 200 mA
* Expected battery life under continuous use: approx. 5 hours (This figure will vary depending on the actual conditions of use.)

Accessories: Dry Battery (Alkaline LR6 (AA) type) x 6, Owner's Manual, Roland Service (Information Sheet)

Options: AC Adaptor: PSA Series, Foot Switch: FS-5U, Foot Switch Cable: Roland PCS-31L