If I am not mistaken the HD Fatshots do meet EPA specifications. Also Supertrapp who makes these slip on for HD have their own Fatshotz with a Z and also meet EPA regs. (check on their website) and in my opinion is a better manufactured product than the one they supply HD, also you can add or subtract the discs as required.
Here is a pic with the Supertrapp Fatshotz on my Limited.
geezerglide
They are approved for 96 CU in bikes not for the larger engines
Screamin' Eagle® FatShotz 2-Into-2 Slip-On Mufflers
Provide a performance and style boost to your 2-into-2 exhaust-equipped Touring motorcycle. Designed for easy installation on the Original Equipment header pipes and muffler hangers, these mirror-chrome flared mufflers are tuned to maximize air flow while keeping the rich exhaust note within the legal limits. EPA stamped, these mufflers are 50-state street-legal on stock displacement engines.
80847-10
Fits 50-state '09-later Touring and Trike models with dual exhaust (except FLHTCUSE, FLTRSE, FLHXSE and '10 FLHX and FLTRX). Installation requires separate purchase of Muffler Clamps P/N 65296-95A (Qty. 2).
MSRP US $429.95