Not sure if this is considered a power head but definitely looks pretty cool.
Riptide Gyre Generator
Riptide Gyre Generator
http://www.coralvue.com/maxspect-riptide-gyre-generatorNext Generation of Water Moving Technology
The Maxspect Riptide is the world's first "Gyre-Generator". Compared to traditional powerheads and wavemakers that are based on propeller nozzle flow technology, the Maxspect Riptide is based on advanced crossflow technology which produces massive horizontal water movement leaving little to no deadspots.