Retractable wrist blade (5e Equipment)
From D&D Wiki
Retractable wrist blade
Martial Melee Weapons
Retractable wrist blades were stored in Jango Fett's right gauntlet. He used them to prevent himself from sliding into Kamino's oceans during his fight with Obi-Wan Kenobi.
Beskar. The helmet have immunity to damage from the blaster fires and lightsaber attacks.
Special. Retractable wrist blade is used while installed on a wrist gauntlet or in a Mandalorian Vambrace.