We at PROSPEED have always put emphasis on function AND form in everything we do! That being said we recently developed our own catch can system that we believe to deliver the best of both by using high quality components, larger -10 valve cover vents, and building each by hand in house! Made in USA! Recommended for all ZL1 owners and a must for those pushing higher power levels than stock! Fully atmospheric release, requires welding of -10 AN fittings (included) on the valve covers, new valve covers available with fittings welded on.