2,600 RPM
Air cooled
$5,300
Open air cooled diesels are not quiet.
But for a permanent hide-out a made-in-Japan rather than China set may be the cat's meow for economical long duration runtimes. The 2,600 speed is especially inviting. Because it is Kubota brand, it will start and run a roof air and perhaps charge batteries at the same time.
Because of shipping costs I would say purchase locally through a Kubota dealership.