This nylon ring fits inside the gearbox turret and locates on the gearbox dowel pin, it also holds one of the two wave washers when performing a shifter rebuild.
Suits MX5 NA 1989-1997
If you are rebuilding the shifter choose the one for your model below
NA 5spd shifter CLICK HERE
NB 5spd/small bush 6spd shifter CLICK HERE
NB large bush 6spd shifter CLICK HERE