Blue Sea Systems, Bussman 187 series marine rated circuit breaker. 

• Combines switching and circuit protection into a single device*
• Clear, single lever operation
• "Trip Free" design cannot be held "ON" during fault current condition
• Waterproof
• Recessed mounting holes for clean appearance
• Large Clearance around terminal studs accept heavy gauge wire lugs
• Robust 5/16 M8 terminals provide high torque connections
• Large lever with vertical/horizontal orientation provides indication of trip status
• Ignition protected - Safe for installation aboard gasoline powered boats
• * Do not use as a switch where high inrush currents are expected.

Clearance stock. Limited quantity.