They are Chinaturbos. They can do consistent numbers in the 300whp - 350whp range per turbo, so almost 700whp for the pair on Race Gas and supporting mods. They have the T25/T28 Turbine housing turbo inlet flange, so it has the correct flange to bolt up to your CA18DET, along with the SR20DET, most KA24DETs, VG30DETT, RB20DET, RB26DETT, etc etc. They were made as exact replicas of the Garrett GT28RS, with the same critical tolerances.
The 0.64AR Turbine housing is ideal for small displacement motors up to about 1.8L for quick spool in the lower RPMs. My car is 1.5L per side, thus the reason for two turbos. RB26DETT is 1.3L per turbo so it is good there as well.