After much research, i figured out that these use quick clip II compatible ear pads. So anything R.E.D. (burton) makes for their helmets after 2009 (beware 2008 and pre audex earpads for cheap on ebay - they are quick clip 1 and not II) will fit the riot helmet. The bad news is, since now they put zippers on their ear pads to just drop in the skullcandies, they don't really sell replacement ear pads anymore for their helmets, unless you wanna get the "audex subwoofer" system.

Unfortunately it doesn't look like the audio ear pads are sold separately on the site...but they are available...check yer local shop????