I fairly positive they are stainless...
I thought so too but FRPP web site states pipes are stainless and tips are 304 polished and chromed stainless. sais nothing about the muffler chambers??? only reason I ask is chambers looks slightly different color than the rest of the setup. If they are completely stainless than I could understand the comparative price to borlas and corsa ect.
2013 V6 Mustang Automatic with the following mods: Roush Hood scoop, 3M Clear braw paint protector, MRT rear window louvers, 3M scotchprint carbon fiber roof wing decklid and scoop, strut tower brace, FRPP axleback exhaust.