The V561 3½ digit loop-powered meter is perfect for applications where a simple inexpensive display is required and no AC power is available. And even if the lighting is poor, the loop-powered backlighting option lets you see the display under any lighting condition. This option gets its power from the 4-20 mA input loop so there is no need for additional wiring and no batteries to ever change. The V561 is in an Explosion-proof enclosure.