4 D Flip Flop

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

4 d
4D or 4-D may refer to: * Fourth dimension *The IRIS-4D family of servers and workstations from Silicon Graphics * Class 4-D, a classification of the Selective Service System * 4-D (psychedelic), a psychedelic drug.
4-D, or 3,5-methoxy-4-trideutero methoxy phenethylamine, is a lesser-known psychedelic drug. It is one of the only phenethylamines that contain deuterium, the other being beta-D. It is also the 4-trideuteromethoxy analogue of 2C-H.
The International Ultramarine Corps, formerly the Ultramarine Corps, is a fictional team of superheroes published by DC Comics. They first appeared in DC One Million #2 (November 1998), and were created by Grant Morrison and Howard Porter.