For serious gravity aficionados only. The ATAC DH 4 is built like a tank for big drops, big rocks – the most extreme downhill trail conditions. The ATAC DH 4 is a downhiller's dream featuring an aluminum body and oversized hollow steel axle. The ATAC system allows you to ‘put a foot down' and clip it back in when needed. The open, self-cleaning design keeps the trail off the pedal, clearing debris and mud every time you clip in.