【Real-Time LED Voltmeter】 Features a large-screen LED display showing battery voltage instantly when switched ON. The screen automatically turns OFF when the switch is OFF, preventing any parasitic drain while providing clear, at-a-glance battery status monitoring. 【Easy Installation & Adjustable Fit】 Designed for standard 15-17mm (0.59"-0.67") NEGATIVE battery terminals. Its unique adjustable-angle mounting base ensures a secure, hassle-free fit even in tight engine compartments – no special tools required for simple DIY installation. 【Robust 250A Continuous Current & Wide Voltage Range】 Engineered for heavy-duty use with a 250A continuous (300A intermittent) rating at 12V. Safely operates across a broad 5-60V DC range, making it compatible with cars, trucks, RVs, boats (12V), golf carts (36V/48V), and battery banks. 【Secure Connection & Premium Construction】 Features a flame-retardant Nylon 66 housing and high-conductivity silver-plated copper internal components for superior corrosion resistance, oxidation prevention, and long-term reliability. Ensures a vibration-resistant connection to prevent power interruptions. 【Essential Battery Protection & Safety】 Provides a master power disconnect to prevent battery drain during storage, protect against electrical shorts, and ensure safety during maintenance. Simply turn clockwise to ON and counter-clockwise to OFF for reliable power control. Top Post Battery Disconnect Switch with Voltmeter