Produced by Ampeg from 1969 to 1971, the "see-through" bass was supposedly created for it greater sustain and ease of manufacture due to its easily cut (like wood) plexiglass body. Unfortunately that material's expansion and contraction made for some tuning problems, somewhat solved by changing tuning machines in later models. Keep in mind that plexi is much heavier than wood and it certainly left quite the impression on my left shoulder. The Dan Armstrong bass and guitar were later re-issued by Ampeg in 1998, manufactured in Japan (of course!).