6 speed Spitfire?

[Mark Gardner <mrgrdnr@ix.netcom.com>]

Hi all - I saw this ad on the internet.  Does anybody know what the
"6-spd double overdrive" is?

Thanks

Mark Gardner   

           79 Triumph Spitfire Sport Inca yellow,new
             black interior,performance exhaust,6-spd
             double overdrive,new pirelli tires,new soft
             top,tonnue cvr,boot cvr,hard top,orginal
             paint,xlnt cond,runs perfect