The Xray T4 '16 & '15 2mm Hard Shock Tower Set is made from 100% premium carbon fiber which utilizes a varying angle layup to provide an uncanny resistance to flexing / twisting.
Not as stiff as most thick kit shock towers but they are very resilient in supporting your rear body mounts. During development we had corner marshals stomp on them, drivers clip sweepers causing a high velocity tumbling wall bangers, and even 4 foot high kart wheels down the straight away in order to let Paulie pass underneath with no failures to date. The set allows you to remove 4 grams of weight from up high which is at least worth 1 second per lap.