ACUITY K-Series Transmission Performance Select SpringsIncreases shifter centering force by approximately 50% Increased spring force makes shifter centering more "snappy" black oxide coated for better oil retention Honda officially calls these the "First 2nd Select Spring" and "Fifth Sixth Select Spring." They are the parts in your transmission that are (partially) responsible for your shifter centering itself when in neutral. By increasing the rate and preload of these springs, it's possible to realize a