The BF-2 Flanger was released in 1980 and discontinued in 2002, making it a long-selling product that shook the sound of countless guitars for a remarkable 22 years until the release of its successor, the BF-3. The BF-2 is a 기념비적인 model in BOSS's long history, being the first compact effector with a four-knob configuration. When it was first sold, it used black-top knobs with horizontal ridges, which were changed to the white-top knobs still used today around 1990. This product is from around the time the white-top knobs were introduced. As for the sound, it has the functionality of a flanger, capable of producing everything from the intensely swirling jet-like sounds characteristic of a flanger to very subtle chorus-like sounds. I purchased it 30 years ago and used it for 3 years, and it has been stored at home in an effector case for 27 years. This is a sale of the unit only. There are scratches on the effector body. Please refrain from purchasing if you are overly concerned about condition, and only purchase if you understand and accept the condition.