Spring valve data Seat pressure - 34 kg (75 lbs) Load - 63 kg @ 10 mm (140 lbs @ 10 mm) Maximum travel - up to 12 mm Made of chrome-silicon steel SAE9254-VBMW - 2.0 16V Turbo B48B20 This kit minimizes the risk of valve vibration and possible engine failure. Recommended for engines with stock and racing camshafts and revolutions above 7500 rpm. The set includes: 16 pcs. conical valve springs, 8 pcs. 5mm titanium retainers, 8 pcs. 6mmmm titanium retainers