Sito Plus has been the standard in basic exhaust performance for many years.  Their pipe for the Vespa and Piaggio 4-stroke 50cc scooters is no different.  Expect modest gains at a very reasonable price.  The place where these pipes really show off is when you combine them with a big bore kit.  We recommmend the Malossi or the Polini.
Brand:  Sito
Fitment: Vespa LX 50, Vespa Primavera 50, Vespa Sprint 50, PIaggio Fly 50
Not legal for use in California on pollution controlled vehicles.  Check local laws before installing.