Feder TiAL klein rot Wastegate & BOV Zubehör extern TiAL Wastegate Spring small red Genuine TiAL spring for F38, F40, F41, F46P, V44, V60 For the adjustment of boost level These springs are used to adjust theminimal boost level of your actuator. Higher boost levels can be achieved by reducing the control pressure using a manual boost valve, electronic boost controller or reprogramming the ECU. Depending on boost target you may need a small or a large spring, or even the combination of both.. You receive ONE spring! The image shows all springs available, you only order one spring as specified above.