This case is designed for 11" rim diameter open-back banjos with short (or short-ish) necks. It will fit a variety of open-back banjos (short-scale 5-strings, tenors etc) as well as some zither banjos. The internal sizes are: 36 ¼" x 12" x 4" This is a nicely-made hardshell case with thick plush lining (that can be modified to accommodate instrument which have slightly larger rims). It has 3 catches, 2 hinges and a nice quality padded handle as well as an internal string compartment. A nice solid case which will give good protection to an instrument.