You may have first seen US Special Forces in Iraq and Afghanistan wear something similar to Benchmark's American Shemagh (pronounced šmāġ).
The Shemagh has many names and crosses into many cultures. Some people call it a keffiyeh, hattah, ghutrah or headscarf. Regardless of what you refer to this cloth as, they are commonly found in arid regions to provide protection from the sun, sandstorms, and dust. Made from lightweight and breathable materials they are perfect for warm weather.
Constructed from inherently flame resistant materials and made in the USA. It was originally developed with an electrical utility to help folks who are drilling into creosote poles during windy conditions. Since it's release, it has become popular for workers who wear FR in dry, arid conditions.