Evercool HDD Water Cooler, Water Block, Heatsink, 5-inch Bay

This is an Evercool water cooling unit for HDDs.
It uses one 5.25-inch bay.
While it appears unused, the hoses and gaskets are old enough that it's recommended not to use them as-is. The hoses still have some elasticity when squeezed. The ring in the last image, possibly a gasket, is hard and lacks elasticity.
It has a weight and coolness that suggests it could also be used as a heatsink.