Maxon '01 Series' pedals were made in the late 80s and sold exclusively to the domestic Japan market. This is basically a take on the Ibanez SM-9, which Maxon made, in a new box. It's driven by a pair of op-amps and has that punchy, thick tone that's hard to get without a cranked tube amp. The EQ is super powerful too. Sounds absolutely nothing like an HM-2, sorry/praise be.

Model: Maxon SM9Pro+ Super Metal
Made: Japan, late 80s
Serial: 166M9P003
Type: distortion, mid-high gain
Power: standard 9v negative supply
Switching: buffered bypass
Mods: battery cover broken, taped closed

Condition notes: used, few scuffs and marks. Note the broken battery cover.
Overall: good condition