Atlas tech produced by research and development. They work by acting as an anchor for the owners aura. The aura is not so much suppressed ad it is redirected. The aura one tries to use is instead redirected through the collar. Since aura can not be used by inorganic objects, with the exception of VERY special objects, the aura cancels itself out. To be used, it must have its wearer's aura imprinted on it, which is a somewhat lengthy process. As such, they do not work in the field, but are essential for imprisoning rogue hunters and huntresses.