The redeem icon is represented with a bracket on the two sides. On the inside of the bracket there will be three X's to represent the items that have been redeemed by the other person.
This Redeem icon is made in Material Design style
developed by Google. This style is based on extremely simplified shapes, thin two-pixel lines, and is optimized for 24x24 px. Unlike other vector icon packs that have merely hundreds of icons, this icon pack contains 5,500 icons, all in the same style and quality.