Tool-bay diskCanonLegendsInfinitiesTool-bay disks were functions that stored equipment for BB units. Usually, more than one was needed. The ones in the droid BB-8 could be replaced or upgraded with minimal reprogramming. Sources The Star Wars BookAppearancesStar Wars: Episode VII The Force Awakens (First appearance) (Unknown)Unknown UnknownNoneStar Wars: Droid Repair Bay (Unknown)Unknown UnknownNone