Bills Motorcycle Plus XR250 and 400 adapter. We build them to fit all 96/97/97/99 Honda XR 250 and 400's. Dirt Bike Magazine featured in their January issue with a good review. We have had very good response to and feedback from our customers. The adapter bolts to the stock muffler replacing its original core. The advantages are clear. It gives the rider the ability to custom tune his motorcycle using any of the SuperTrapp tuning disks to suit his needs. 4 plates can be used for a quiet dual sport or up to 18 plates for a racing application. It also serves as a spark arrestor and adjusts to meet I.S.D.E. sound checks. The system develops better power and is lighter than the stock exhaust. I have personally tested it on my own XR330 for over a year now and have found it is the trick set up. The adapter sells for $49.95. The complete package costs between $85 and $115 which is half the price of competing systems.. Dealer inquiries are welcome. If you are interested you can email us via the contact page or call toll free 1-888-806-1153 (585-1153).