the parma 50cc is actually labeled Zeta, so I assume they just took whatever zeta had left and rebranded it.
they are actually probably as good as stock, if not worse.
the piston has the bottom of the side skirts cut out, and windows cut into the sides of the piston, and the piston has a higher dome than a stock one, but the intake is narrower and taller than the 30mph cylinders, and the exhaust is pathetically small. Dont buy it.