On this parts fiche the Gasket (nas) is the most specified component.
Parts such as the Turnsignal Lamp: Lamp Assembly,front Turn Signal, Screw(3x30), Gasket (nas), Gasket (nas) are included in the Gsxr1100 1989 (k) (e01 E02 E04 15 16 17 18 21 22 24 25 34 39 53) Turnsignal Lamp parts fiche.
This schematic depicts all components used in the Gsxr1100 1989 (k) (e01 E02 E04 15 16 17 18 21 22 24 25 34 39 53) Turnsignal Lamp partslist.