RIVA SPARK PERFORMANCE WATERBOXDeveloped on RIVA's Dyno and tested extensively on the water, this waterbox features radiused exhaust tubes and dished end caps for optimum exhaust flow. Unique exhaust baffle design increases the low end power and mid range pull of your SPARK's 900cc engine. Delivers up to 5hp on modified engines along with significant torque gains. High strength aluminum construction will survive backfires and meltdowns. A great add on for RIVA Exhaust Kits!