Blue Sea 6004200 Single Circuit ON-OFF w/Locking Key - Black

The Blue Sea Systems 6004200 Single Circuit ON-OFF with Locking Key in black is a heavy-duty marine battery disconnect switch engineered for small gasoline and diesel engines, outboards, and auxiliary power systems. With a 300-amp continuous rating, this switch delivers the electrical capacity needed for dependable engine shutdown and circuit isolation on everything from center console fishing boats to cruising sailboats and compact sportfishers.

Built to withstand the harsh marine environment, the switch features tin-plated copper studs that resist corrosion from salt spray and moisture while maintaining maximum electrical conductivity. The one-piece stud design and stainless flange nuts eliminate the loosening that can occur with traditional multi-part terminals, a critical reliability factor when engine shutdown depends on a solid electrical connection. Studs accept 3/8-inch (M10) ring terminals, and the 7/8-inch stud length accommodates multiple cable connections without requiring adapters or compromising contact integrity.

This switch is ideal for boat owners who need dependable battery isolation for emergency shut-down, seasonal storage, or theft prevention. The locking key feature provides security in unattended situations, preventing accidental engine starts. Weekend anglers, cruising sailors, and offshore fishing enthusiasts rely on this type of disconnect to protect their electrical systems and ensure safe engine management in unpredictable conditions on the water.

Blue Sea Systems is recognized throughout the marine industry for precision electrical components that meet the demanding standards of commercial and recreational vessels. The 6004200 represents the brand's commitment to durability and performance in saltwater applications where standard automotive switches fail.