This has a little more gain on tap than the ubiquitous SD-1, plus it's a slightly more trucks-and-diggers yellow. Nice little sturdy overdrive with plenty of midrange grunt and punch. 

Model: Boss OD-3
Made in: Taiwan, recent model (serial sticker missing)
Type: mid gain overdrive
Power: standard 9v negative adaptor or 9v battery
Equivalent new street price (approx): $139aud
Mods: none
Accessories: original box and docs
Condition notes: good condition, minor cosmetic marks, original baseplate sticker missing