Mad Catz F.R.E.Q. M Wired Headset - Matte Black. Now the same headset can go wherever you go. The F.R.E.Q. M Mobile Stereo Headset is the ultimate rich-stereo headset sporting a lightweight, foldable aluminum chassis for easy transport. With two unique in-line cables, this all-in-one headset can be used with a PC, Mac, or smart devices.