The headband is from T-E M/F. It will show up in accessories near the WA snake armband. There are two color channels.
I very much suggest that you download aWT's hat sliders for this headband, as it will clip with almost everything if just left plain.
It is an accessory, so the texture files are smaller, therefore patterns will be blurry, unless you choose to get the HQ Mod, which will fix the problem, as I have given them normal sized texture files.