Tough mar-proof black vacuum-formed ABS plastic shell with aluminum valance. Plush lined. All hardware is backed by steel washers. Interior is foam lined. These cases are manufactured to withstand the rigors of "student abuse," and their universal designwill fit 95% of all instruments. This medium frame tuba case will fit horns with an max length of 37" and a bell size of 20". Some of the common horns this case will fit are, St. Petersburg, Conn 5J, 12J, and 2-5J, Meinl Weston 2145 and Meinl Weston 18 to name a few. - the manufacturer