The MASCR-4 fires a magnetically accelerated aerosol payload of a proprietary crystallization agent — a supersaturated ionic compound developed by Tessera Corponation under a materials science patent — that is absorbed transdermally and through mucous membranes upon impact. Once inside the body, the compound undergoes rapid crystalline precipitation specifically in the synovial fluid of major joints when exposed to the low-frequency resonance field the weapon continuously projects at its target. The result is acute crystalline arthropathy: joints seize, cartilage abrades against crystalline deposits, and mobility collapses within sixty to ninety seconds of exposure.

The weapon's two-stage mechanism — aerosol delivery followed by resonance-triggered precipitation — gives operators tactical control over timing. The crystallization agent alone is inert; it must be activated by the resonance field. An operator can tag multiple targets with aerosol rounds, then trigger crystallization selectively or simultaneously. The effect is agonizing and temporarily disabling but not inherently lethal, and the crystalline deposits dissolve naturally over twelve to thirty-six hours as the body flushes the compound. Permanent joint damage occurs with repeated exposures or in subjects with pre-existing synovial conditions.

Tessera Corponation markets the MASCR-4 through a subsidiary under a 'non-lethal compliance' classification, a designation that has been challenged by three separate medical bodies and upheld on technical grounds each time. The weapon is available at Tier 4 through licensed security contractors and is considered standard equipment for certain high-end private correctional facilities. Its presence on the street is considered a reliable indicator of institutional backing behind whoever is carrying it.