Barry Allen, the second Flash, uses this ring to compress and conceal his costume while operating in his civilian identity. By thumbing a small stud on the side, the ring opens and releases the costume, allowing Barry the ability to to change into it at super-speed. He has stated the ring shoots
Flash's Costume Ring is a small ring with a spring-loaded opening.
Barry Allen, the second Flash, uses this ring to compress and conceal his costume while operating in his civilian identity. By thumbing a small stud on the side, the ring opens and releases the costume, allowing Barry the ability to to change into it at super-speed. He has stated the ring shoots out the costume with force equal to nine airbags. The electromagnetic properties of Barry's Speed Force energy create a thermal expansion, allowing the pieces of the suit to shrink and expand, as well as allows him to conduct the pieces around his body at will. Barry originally created the ring for practicality, as well as a symbol to remind himself of why he is the Flash. For this reason, he decided to take both his parents' wedding rings and forge them together to create his ring.
Wally West, the third Flash, also used one of these rings, although he eventually stopped, having learned to manifest a suit out of the Speed Force. Barry's grandson, Bart Allen, used a similar ring to hide his costume while he was the Flash, and another to house his Impulse and Kid Flash costumes (he does not remove this ring under any circumstances, at least not willingly).
The original costume ring was kept by Eobard Thawne, and passed into the possession of Hunter Zolomon after Thawne's death. Hunter would use the suit after dubbing himself the new Flash 
- Bart's first costume ring, that in which he stored his Impulse costume, was a gift from Wally West, and a replica of Barry's original.
- Green Arrow used the ring given to him by Barry Allen as a gift when he proposed to his longtime girlfriend Black Canary.
- The Flash has shown the ability to vibrate and compress his molecules to actually hide himself inside of the ring when the situation calls for it.
- Appearances of Flash's Costume Ring
- Item Gallery: Flash's Costume Ring
- Images featuring Flash's Costume Ring
Links and References