PTY is managed by PIMCO. Purely fom investment strategy perspective, they are not much different from other income funds, which means they are primarily investing in government bond, corporate bond, CMBS, Muni, MBS, etc. They use leverage just like many other high-yield income fund, which means higher risk.
However, PIMCO is considered as one of the best, if not the best, asset management firm. I have a few PIMCO CEFS (closed end fund), but only mention PTY here due to its 20 years consistent performance (never cut dividend in 20+ years of history), with arguably the best fund management team on the market.
PIMCO also has other CEFs that give even higher yield but I dont feel comfortable mentioning them due to their shorter history