This is a Rousseau Jazz Model JDX, number 7. Like the 7R, this model is not often seen on the market. I used it for playing pops, funk, and fusion pieces in wind bands (such as the standard "Takarajima" and "Omen of Love"), as well as in big bands. The interior is unique; it's not a high baffle, but the side walls narrow sharply. It gives the impression of producing a standing sound when blown into, and a low baffle sound otherwise. *Because this is a Rousseau from an earlier period, the ligature size is between tenor and baritone. Extended tenor ligatures like BG, JLV (adjustable diameter), Silverstein, Bamboo (doesn't require diameter adjustment), and Sengoku ligatures will fit.