This Perko switch allows you to shut off all power to your devices or if you use them to control your Run & Gun Chargers. This unit is required for the 28 volt regulator for the forward facing sonar black boxes. Now you can turn off the forward facing sonar units when you elect not to use them, but still want the head units on. INCLUDED - On/Off Perko Switch - 4 stainless steel mounting screws SPECS 275 amps continuous cranking rating 1250 amps Dimensions: 2.75" x 2.75" x 3H inches Essential Power Control for Your Marine Electronics SystemThe Perko On/Off switch is a required component for the VR28 28V forward facing sonar converter, and a smart addition to any Run & Gun DC charger setup. It gives you precise control over your electronics power — shut down your FFS units independently while keeping your head units running. Required for VR28 sonar converter — controls power to forward facing sonar black boxes independently 275A continuous / 1250A cranking rating — handles the demands of high-current marine systems 4 stainless steel mounting screws included — corrosion-resistant hardware for marine installation Compact footprint — 2.75" x 2.75" x 3"H fits easily on any console or panel