These new spindle arms help fine-tune corner entry, middle, and exit steering response to your liking. Steering Response: Less initial steering, more mid and exit steering. When Recommended: Higher grip, or tighter tracks. Ackerman: Less than TKR9047B TKR9047A spindle arms must be used with TKR9041X spindles. Vehicle Compatibility TKR9047A - Spindle Arms (EB/NB/ET/NT48, requires TKR9041X, Type A) is not included with any kit. This can be used with the EB48 2.0, ET48 2.0 and NB48 2.0 vehicles and should be a direct replacement for the stock part or used as a new feature. Please use the instruction manual for the kit(s) listed to verify compatibility and no additional items are necessary before purchasing.