This is a set of two 6 mm exhaust pipe studs for performance exhausts from NCY These replacement 6mm exhaust studs are used on NCY exhausts for 50cc enginesDescription This is a set of two 6 mm exhaust pipe studs for performance exhausts from NCY. These replacement 6mm exhaust studs are used on NCY exhausts for 50cc engines.Let Monster Scooter Parts be your source for NCY scooter parts and accessories.0500-1035 ? WARNING California Residents: Proposition 65 Warning