What is a Dreadnought Guitar?
A Dreadnought guitar case is a specialized case, so if you are considering purchasing one, please make sure that your guitar body is Dreadnought-sized.
Basically, there are three standard shapes of acoustic guitar: Standard, Jumbo and Dreadnought.
Each has a different shape and so requires a different guitar case.
Comparison of Dreadnought and Standard Acoustic Guitar Shapes
Martin D-41 Dreadnought Guitar 1081995
PRS Tonare Grand Standard