61cm quadruple torpedo mount
"A quadruple tube of heavy-hitting 61cm torpedo. Comes with reloading device to reload torpedoes in quick succession, thus providing more opportunities for pursuance. Fitted on fleet destroyers of post-Shiratsuyu class, as well on modernised heavy cruisers." [1]
The tag applies to the Kantai Collection fairy.
The fairy who maintains this equipment has blue hair worn in short twintails secured with red ribbons, and wears a school swimsuit and diving mask. She occasionally wields a trident.