The lightweight aluminum alloy material is durable and improves the overall performance of the shock absorber , Aside from the great looks, aluminum alloy will not flex as much as plastic under stress or during high ambient temperatures. Compatible with Arrma Series ARA4305V3 1/10 VORTEKS 4WD 3S BLX STADIUM TRUCK RTR,ARA4105V4 1/10 VORTEKS 4X2 BOOST MEGA 550 BRUSHED , ARA4105SV4 1/10 VORTEKS 4X2 BOOST MEGA 550 BRUSHED STADIUM TRUCK RTR