This kit reinforces your Polaris RZR rear frame section. If you drive your RZR like a madman or like to jump it, this kit is a must! The machined tubes slide into the rear chassis tubes, increasing the thickness by 130% The kit also includes machined end pieces with rubber o-rings that will seal out mud and water. All pieces come in a Zinc Chromate finish to resist corrosion. Includes stainless steel hardware and detailed installation instructions.