Polaris RZR XP900 Series UHMW A-Arm Guards. Factory UTV RZR XP4 900/XP 900 a-arm guards offer the best in a-arm protection. Constructed from ultra tough and slippery UHMW these guards protects your a-arms from the off road abuse you love to put them through 1 set of front guards. All necessary mounting hardware included. This is the same protection Factory UTV Support racers have used to protect their race UTV s and win every major Pro UTV Endurance Championship race including the Baja 500, Mint 400, King of Hammers, San Felipe 250 and Silver State 300.