This is the follow up to ZZP's popular 3" straight through resonator that we use in the Ecotec/Sonic/Cruze/and other cat-backs. Our compact (medium) version provides 75% of the drone and noise dampening of the larger resonator in a vastly smaller package. Our unique three chamber design cuts rasp down, gives your exhaust better tone, and helps reduce overall volume on your system. Many competitor's (Borla, Vibrant, Flowmaster, Dynomax, etc) resonators are fully straight through or lack the quality packing that we use, meaning only a slight change in tone and still leaves a lot of rasp. You can put these resonators basically anywhere and they will still provide that great ZZP exhaust note you've come to expect.