These are the same injectors demanded by many of the most discriminating Subaru tuners including Cobb.

Each set is individually tested and flow balanced in-house to within a 1-2% variance. The results are included in your custom flow report that accompanies every set of DW injectors. There flow report also includes additional set-specific data useful for tuning. DW STi injectors also feature:

100% drop-in fitment
OEM 12-orifice atomization plate (4-hole for 550's and 650's)
Upper and lower o-rings
12-month comprehensive warranty