720p HD — acceptable for standard viewing, though not true high-bitrate 1080p or remastered quality.
Likely a pirated encode from Vegamovies (known for torrent and direct download releases). No guarantee of original Blu-ray source or proper encoding settings.
Here’s a review of the release you mentioned:
Episode 164 of DBZ Kai covers material from the final arc (Majin Buu saga, Kai’s “The Final Chapters”). It’s a solid episode in terms of pacing, with reduced filler compared to original Z .