From their website:
# Garrett T3's, T4's, and most T3/T4's
# Garrett T2, T25, and T28
# Mitsubishi TD04's, TD05's, and TD06's
# IHI RHB5 Series Turbos
# KKK K03, K04, K06's
# Most KKK K14, K16, K24, K27, K28, and K29 Turbos
Further down, under Rebuild Kits:
KKK Complete Rebuild Kit
This is a complete turbo rebuild kit for KKK K03, K04, and K06 turbos. This kit will fit Audi S4 bi-turbo, Audi A4/A6 1.8T, VW Passat/Jetta 1.8T, and many more.
There are many different kits available for other KKK turbos such as the K14, K16, K26, etc..