Ferrea valve safeguards are manufactured from high quality 4140 steel and machined to exact tolerances. The security features are heat treated for maximum strength and finished in black for an attractive appearance Fits: VW GOLF / JETTA 2.0 L - DOHC 16 VALVE (9A) - 1990-1992 Reference: 7 mm. Radial groove. Use with Ferrea Titanium # E11084 Ferrea valve locks are manufactured from high quality 4140 steel and machined to exact tolerances. Protections are heat treated for maximum strength and finished in black for an attractive look. Fits: VW GOLF / JETTA 2.0 L - DOHC 16 VALVE (9A) - 1990-1992 References: 7 mm. Radial groove. Use with retainers Ferrea Titanium # E11084