A - Series: - Fiberglass packed - Suits all engine types with 4" to 5" exhaust systems

B - Series: - Suits turbo engines with exhaust systems from 2" to 5" & naturally aspired engines with exhaust systems from 2" to 4" 

C - Series: - Suits all engine types with exhaust systems from 3" to 5"

D - Series: - Baffled reactive muffler Suits Natural aspirated engines with exhaust systems from 2.5" to 5"