P Core 4 Yfz450r '09Features: U. S. Forestry approved spark arrestor Megamax II is a reverse cone megaphone design and can be run open for closed course or with discs for off road riding FMF has radically improved the PC IV by creating a modular end cap that allows for easy tuning with various end caps that alter the power band around the needs of the rider Quickly changed, the standard Hi Flo 2" end cap, the optional 1 3 4" end cap for a smoother power delivery and the