From Guns.com:

While the full-length 20-inch SCAR 20S series has long listed a 6.5CM variant, the SCAR 17 has typically just been available in 7.62 NATO. The SCAR 17S DMR includes a lot of upgrades over the standard model, including the SSR precision buttstock assembly and Geissele 2-stage trigger seen on the SCAR 20S line.