The KPS-9 Rattler is the cheapest submachine gun on GLMZ. At Φ400, it costs less than many handguns, and Kang-Petrov manufactures it with that price point as the primary design constraint. The weapon is a simple blowback-operated SMG chambered in 9mm brass-cased, with a stamped steel receiver, polymer grip, and a 32-round stick magazine. There is no BCI link, no electronic sight, no onboard computer. The sights are molded into the receiver.

Reliability is inconsistent. The Rattler functions adequately when clean and properly lubricated, but the loose tolerances that enable mass production also admit contamination. In dusty or wet conditions, malfunctions increase noticeably. The weapon's accuracy is sufficient for engagements inside 50 meters, but beyond that distance the combination of fixed sights and a short barrel makes consistent hits challenging.

None of this matters to the Rattler's customers. The KPS-9 exists because violence is not exclusively a privilege of the well-funded. For Φ400, a person in a Tier 1 zone gets a weapon that fires 30 rounds of commonly available ammunition. It is not a good weapon. It is an available weapon. In a world where availability often matters more than quality, the Rattler sells millions.