The Kerbl 372040 PowerShock B290 is a versatile 12V battery-powered fence energizer set, ideal for short to medium electric fences. It includes a reliable 12V 18Ah GEL battery, making it perfect for mobile installations or areas without mains power access. This energizer features an on/off switch and visual controls for fence voltage and battery status. It delivers 2.9 J of charge energy and 1.9 J of discharge energy, with a maximum voltage of 10,500 V and 4,500 V at 500 Ohm. Suitable for theoretical fence lengths up to 60 km, 10 km with medium vegetation, and 3 km with heavy vegetation, consuming 130 mA.