I picked up one of these....a very handy and practical bit of headgear whether you wear it alone as a skull cap to keep the wind from completely blowing your hair amiss or simply under the helmet to absorb sweat and save the inner liner of your helmet. I find that installing a pair of ear plugs and then using the dust bandit skull cap fashion under the helmet and over the ears.....does a great job of eliminating excess noise during longer rides.
They are very comfortable. The do-rag look comes with a perceived "stereotype" though. It seems that all the Harley riders sport do-rags. On hot days like today it seems that about 60% or more of the riders I passed were helmetless and wearing a skull cap of some sort.