Blue Sea 4009 CableCap - Black 0.47 to 0.13 Stud

The Blue Sea 4009 CableCap in black is a professional-grade insulating terminal cap designed to protect and isolate stud-type connectors on high-amperage automotive devices. Whether you're working with alternators, starters, windlasses, or custom electrical system upgrades, this component prevents accidental short circuits and corrosion on exposed studs. Built by Blue Sea Systems—a trusted name in marine and automotive electrical solutions—the 4009 CableCap addresses a critical safety gap that many DIY builders and professional mechanics overlook when upgrading charging systems or auxiliary power distribution.

This CableCap features dual stud sizing: 0.47-inch and 0.13-inch connection points, making it compatible with a broad range of factory and aftermarket terminals. The black engineering-grade insulation withstands vibration, temperature fluctuations, and engine bay exposure without cracking or degradation. Installation is straightforward—simply slide the cap over the exposed stud and secure it firmly, creating a sealed barrier that blocks moisture, dirt, and accidental metal contact. The compact 3 x 2 x 4-inch form factor fits tight spaces around battery terminals, alternator posts, and starter solenoids without interfering with belts, hoses, or adjacent components.

Mechanics upgrading dual-battery systems, auxiliary charging circuits, or winch setups will find this cap essential for preventing catastrophic electrical faults. Anyone customizing a truck's electrical infrastructure, installing a secondary alternator, or hardening an existing system against vibration-induced corrosion should carry spares. The 0.47 to 0.13 stud range covers standard automotive electrical studs, making the 4009 a universal choice for restoration work, hot rods, and modern vehicle modifications. At just 0.3 pounds, it's lightweight enough to stock multiple units without adding measurable weight to your tool kit or spares inventory.