The size of the shell is 20-50 mm. The maximum recorded shell length is 56 mm.
This sea snail has an arched, rounded shell. On the inside of the shell there is a white "deck" which causes the shell to resemble a boat or a slipper, hence the common names. Some of these may be flat, slightly arched, or arched heavily. The 'Flat slipper shell' is also another type of slipper shell.