Mercury - 1st Mate Captain's Wearable Fob Kit Safety & Security Accessory 98-8M6007943. Overview. The captain's wearable is the heart of the 1st Mate system-it keeps the safety features active, enables engine authorizations, and provides the overboard-alert link the system relies on. The Mercury 98-8M6007943 Captain's Wearable Fob Kit gives you an additional or replacement fob along with two convenient ways to carry it: a red wristband and a carabiner clip. It pairs easily with any 1st Mate syst