Lascar DPM 500 Series 3.5 Digit LCD Panel Meters – Lascar DPM 500S, This panel mounting meter is a compact unit that has a DIL-40 IC format that allows the meter to plug directly into a DIL socket or can be mounted using the snap-in bezel. This single rail version has a built-in negative rail generator, enabling the meter to measure a signal referenced to its own power supply 0V. Lascar DPM 500S 3.5 Digit LCD Voltmeter