Size 15 Flip Flop

flip flop
A light sandal, typically of plastic or rubber, with a thong between the big and second toe
a backless sandal held to the foot by a thong between the big toe and the second toe
A backward handspring
An abrupt reversal of policy
interchange: reverse (a direction, attitude, or course of action)
reversal: a decision to reverse an earlier decision

size
cover or stiffen or glaze a porous material with size or sizing (a glutinous substance)
Extensive dimensions or magnitude
(used in combination) sized; "the economy-size package"; "average-size house"
Each of the classes, typically numbered, into which garments or other articles are divided according to how large they are
the physical magnitude of something (how big it is); "a wolf is about the size of a large dog"
The relative extent of something; a thing's overall dimensions or magnitude; how big something is

15
fifteen: being one more than fourteen
The Plus 15 or +15 Skyway network in Calgary, Alberta, Canada, is the world's most extensive pedestrian skywalk system with a total length of and 59 bridges. The system is so named because the skywalks are approximately 15 feet (approximately 4.5 metres) above street level.
fifteen: the cardinal number that is the sum of fourteen and one