Eastman CA1312B Viola Case The Eastman CA1312B 15"-15.5 Viola Case is designed to be both lightweight and durable, providing comfort for the user as well as security for the instrument. Each Dart Shaped Case features a Cordura cover with a music pocket, soft velour padded interior with an accessory compartment, two bow spinners, and room for a shoulder rest. Two shoulder straps are included.