The PZO-4 is a black market modification of the legitimate PGM-4 gel micro-bead, produced by street-level armorers who replace the standard piezoelectric crystal array with higher-output crystals salvaged from industrial actuators. The resulting bead delivers approximately three times the electrical discharge of a standard PGM-4, converting the CDP-2 'Bruiser' from a technically-non-lethal capillary disruption tool into a weapon capable of cardiac arrest at close range.

The modification process is crude but effective. Street armorers crack open legitimate PGM-4 charge packs, extract the beads, dissolve the gel matrix to access the crystal array, replace the crystals, re-encapsulate in fresh gel, and reseal the charge pack. The resulting product is visually identical to a standard PGM-4 and passes cursory inspection, but the electrical output is far beyond the weapon's designed parameters. The CDP-2's charge settings — originally Non-lethal, Standard, and Overcharge — become Standard-lethal, Extremely-lethal, and Weapon-damaging when loaded with PZO-4 beads.

The overcharged crystals also generate more heat during the piezoelectric activation, which degrades the gel matrix faster and reduces the bead's shelf life from 18 months to approximately 3 months. Expired PZO-4 beads have been known to activate prematurely in the magazine, producing electrical discharge inside the weapon that can injure the operator. The quality variance between street armorers means that PZO-4 beads from different sources can differ dramatically in output and reliability.