alt=A Long Island Rail Road M9, showing both over-running and under-running third rail shoes.|thumb|A Long Island Rail Road M9, showing the dual-type contact shoe.
Alt=a lonG island raiL road M9, SHOwing both oveR-ruNniNG aND undEr-rUnninG Third rail Shoes.|thuMB|a LoNG islanD rail roaD M9, SHOwing The DUAl-TypE contAcT SHoe.