Brand new shifter shaft cover (shift lever retainer) gasket. The cover (also known as reverse blockout) has different appearances in different vehicles but it is always the 4-bolt aluminum cover that bolts to the rear side of the transmission near the top, securing the shifter shaft inside.
2000-05 Celica GT, GTS with Manual Transmission
2000-05 MR2 MT or SMT
2003-08 Corolla/Matrix/Vibe Manual Transmission
2005-12 Elise, Exige, 2-eleven with 1ZZ or 2ZZ engine
#33584A in diagram