A surgical stapling assembly configured to receive a staple cartridge therein, wherein the staple cartridge comprises a lockout key, a cartridge body, a plurality of staples removably stored within the cartridge body and a sled configured to eject the staples from the cartridge body, wherein said surgical stapling assembly comprises: a first jaw (3 0010); a second jaw movable relative to said first jaw between a clamped configuration and an unclamped configuration; a firing member configured to push the sled of the staple cartridge to fire the staples during the staple firing stroke; a first lockout configured to prevent said firing member from advancing from its unfired position through a partially-spent staple cartridge and to be defeated by the sled pushing said first lockout into an unlocked configuration; and a second lockout configured to prevent: said firing member from advancing through an improper staple cartridge; and said second jaw from moving into said clamped configuration when an improper staple cartridge is present and when no staple cartridge is present, wherein said second lockout comprises: a first lockout flange configured to prevent said second jaw from moving into said clamped configuration; and a second lockout flange configured to prevent said firing member from being advanced distally, wherein: said second lockout is configured to be defeated by the lockout key of the staple cartridge pushing said first lockout flange and said second lockout flange in a lateral direction relative to said firing member into an unlocked configuration to permit said second jaw to move into said clamped configuration and to permit said firing member to be advanced through the staple firing stroke when said staple cartridge is properly installed within said surgical stapling assembly. a first jaw (3 0010); a second jaw movable relative to said first jaw between a clamped configuration and an unclamped configuration; a firing member configured to push the sled of the staple cartridge to fire the staples during the staple firing stroke; a first lockout configured to prevent said firing member from advancing from its unfired position through a partially-spent staple cartridge and to be defeated by the sled pushing said first lockout into an unlocked configuration; and a second lockout configured to prevent: said firing member from advancing through an improper staple cartridge; and said second jaw from moving into said clamped configuration when an improper staple cartridge is present and when no staple cartridge is present, said firing member from advancing through an improper staple cartridge; and said second jaw from moving into said clamped configuration when an improper staple cartridge is present and when no staple cartridge is present, wherein said second lockout comprises: a first lockout flange configured to prevent said second jaw from moving into said clamped configuration; and a second lockout flange configured to prevent said firing member from being advanced distally, a first lockout flange configured to prevent said second jaw from moving into said clamped configuration; and a second lockout flange configured to prevent said firing member from being advanced distally, wherein: said second lockout is configured to be defeated by the lockout key of the staple cartridge pushing said first lockout flange and said second lockout flange in a lateral direction relative to said firing member into an unlocked configuration to permit said second jaw to move into said clamped configuration and to permit said firing member to be advanced through the staple firing stroke when said staple cartridge is properly installed within said surgical stapling assembly.