This is turbo piston ring, which are used for GTX5533R Gen2 98mm and other GTX turbine shaft wheels.

Custom GTX5533R Gen2 98mm dual ceramic ball bearing turbo for a special application

Turbo turbine shaft wheel GTX5533R Gen2 102mm exducer (custom)

Turbo ceramic ball bearing 16mm shaft GTX5533R

Turbo Wastegate Rattle Flapper Repair Rebuild Kit, VW GOLF GTI MK6 RHF5, EA888 Gen2 Transverse

Point milled Compressor wheel GTX3071R GEN 2 Forward 54mm x 71mm 8 0 blades