Honda RA168E showed overwhelming performance in F1 series in the 1980's; the turbines for this engine were the symmetrical layout twin turbines. The ideal twin turbines layout for the V-shaped and horizontally opposed engines is a symmetrical twin turbine layout. 
However, 99% of turbines made by turbine manufacturers are the right-hand rotation turbines, and left-hand rotation turbines are rarely made; therefore, it was almost impossible to make symmetrical twin turbines.
HKS developed and manufactured in-house symmetrical twin turbines; HKS' original symmetrical twin turbines are now complete.
The symmetrical twin turbines included in GT Full Turbine Kit for R35 GT-R, which are highly rated by R35 owners from all over the world, are now available to purchase as a set independent of the rest of the kit.
The flanges for turbine inlet/outlet and gaskets are available separately as optional parts.