Shoe ,  Insert ,  XR1-TBS XR Race Inserts are crafted from billet aluminum in an array of sizes.

 Meant to change when boost is activated, a smaller opening boosts quicker and a bigger opening produces more boost on the top end.  A quick way to tune your blower at the track, these inserts are available only for the race series blowers.

Available in:   

• 11"   -10.5"  -10" -9"  -8" - 7" - 6" -5.5"
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