Our official website: https://accordion-bayan.com Our shop in Etsy: https://harmony4life.etsy.com Our shop on Reverb: https://reverb.com/shop/kostiantyns-gear-bazaar-3 Our shop on eBay: https://www.ebay.com/str/innerharmony This is a great Russian concert button accordion (bayan) Tula 302 with Double Cassotto and Converter Bass System. This vintage button accordion (bayan) was made in Tula, Russia. Tula musical instruments have very high quality. Tula bayans are considered to be the best bayans ever made in Russia. This bayan has a converter bass system. It has a switch on the bass side that allows it to play as a free bass or as a Stradella! A free-bass system is a system of bass buttons on an accordion, arranged to give the performer greater access to playing melodies on the left-hand manual of the instrument and to forming one's own chords, by providing a button board of single-note buttons with a range of three octaves or more, in contrast to the standard Stradella bass system which only allows bass notes (range of a major seventh) and preset major, minor, dominant seventh, and diminished chords. This button accordion (bayan) will be good for any advanced professional users for concerts and shows of any kind