The Berk Technology high flow catalytic converters are designed to be much less restrictive than stock, letting you unlock some of that lost power while still serving the function of converting harmful exhaust gasses into something less poisonous. The Berk Technology cats have a 200 cell count spiral wound metallic substrate. The substrate is the catalyst saturated honeycomb-like stuff inside the cat that the exhaust gasses pass though that does the cleaning of the exhaust stream. A metallic substrate has thinner walls with less cross sectional area than the ceramic material used for the honeycomb in most factory cats.

Thinner walls mean larger internal passages in the honeycomb and thus less backpressure. Each passage is called a cell and a 200 cell count means that this honeycomb has large diameter cells for low restriction. Stock cats usually have cell counts in the 400 range and thicker walls on the cells making for much more flow restriction.