Предположу, что это поручень/ступень для доступа к поклаже на крыше.
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Броня.
http://www.mountainvistafabrication....mor-ZJQPA1.htm
Protect the back corners of your Jeep from trees and other obstacles that aim to break your back windows and dent in your sheet metal. This armor is designed to spread the force of accidental collisions over the entire plate, resulting in less damage from harder hits and no damage from milder accidents