The belt requires attunement. Once attuned, it grants the following:
The attuned gains resistance to psychic damage. In addition, they are immune to being paralyzed or petrified and cannot be knocked prone.
As an action, you can channel your anger to produce a shock wave of thunderous energy, as with the Thunderwave spell. The spell has a DC of 16 and is considered to be cast at fifth level. Once used, you cannot use this feature again until you complete a short rest.