exhaust restrictor plate for Aprilia, Beta, Derbi, Rieju

Restrictor plate for exhaust manifold. Following any performance upgrades, it may be necessary under certain circumstances to return the exhaust system back to factory. This restrictor plate means the original power can be restored and the exhaust system regains its road legal status, as long as no other modifications have been carried out. Only suitable for original manifold with 52mm hole spacing. Fits Aprilia, Beta, Derbi and Rieju vehicles.