AS21 10P Aluminum Switch Panel with Overload Protector, Ammeter, Voltmeter and Power Socket The AS21 puts ten switch positions, an overload protector, a current and voltage meter and a 12V power socket onto a single aluminium face plate. Yards and van builders use it as the main distribution point on a dashboard: one cut-out, one wiring loom, and every accessory circuit on the helm is switched, protected and readable at a glance. It works equally well on 12V and 24V systems.