The plenum reinforcement inserts are made from billet 6061 Aluminum by Riffraff Diesel Performance and are Made in the USA. The inserts allow you to clamp down as hard as needed with T-bolt clamps so that you don't have any boost leaks. This is a budget friendly option to buying full billet plenums. Easy install, no special tools needed.
These were designed so as to add the least restriction possible while providing more than adequate structure for clamping. The Plenum Inserts have been machined to within .164" of the OEM diameter so there will not be any measurable affect on EGT's or flow.