Vintage early 1900′s 18 size Ball Model case. Yellow gold filled screw back & bezel case signed inside back Keystone Watch Case J. Boss Guaranteed 20 Years Ball Model. Note: case shows wear. Back and bezel screw on and off great. Bow is nice and tight. If you need a case for your 18 size Ball watch here it is! I have many more items coming up for sale! Be sure to check out all my other items I have currently for sale.