Just rebuilding my engine and bought a new ProX piston. Rings are marked with a small ´R´ mark. They are RIK. Shall i assemble the rings with this ´R´ mark facing up or down or it makes no difference??

Another thing, ProX piston box also indicate it fits Honda CR 250 97-2001...is that the same piston??

The piston is correct, markngs usually go up.

Piston is similar indeed, Many thanks for your reply.
Brgds