Speed nut, ST4.8.

To fit:
928 1987-1995 Used in the front spoiler, wheel housing liners, and front body section
959 1987-1988 Used in the exterior rear panelling, underbody linings, and the front bumper
968 1992-1995 Used in the wing, front and rear bumper assembly and headlamps
911 (964) 1989-1994 Used in the underbody linings, wheel arch liners, front and rear bumper and sill covers
911 (993) 1994-1998 Used in the underbody linings, wheel arch liners, front and rear bumpers, door sill trims
911 (996) 1998-2005 Used in the wheel arch liners and front bumper assembly
911 (997) 2005-2008 Used in the front bumper assembly
Boxster (986) 1997-2004 Used in the underbody linings, wheel arch liners and front bumper
Boxster (987) 2005-2012 Used in the front bumper assembly
Cayman (987C) 2006-2012 Used in the front bumper assembly