These original vintage pedals made in Japan are known to be the best.
This BOSS HM-2 was manufactured in December 1985 according to the Boss Pedal Serial Decoder. BOSS HM-2 was launched in October 1983. The BOSS HM-2 is well known for being used by Shawn Lane and David Gilmour of Pink Floyd.
I am the original owner. Kept in smoke free studio and stored as it was rarely used. There are a few scratches, but it still works perfectly. See pics.
It works fine with a 9v power supply. It is in very good condition. The serial number is 568300