Blue Sea Systems ST Blade Fuse Block w Cover - 6 Circuit The Blue Sea ST Blade Fuse Block consolidates branch circuits and in-line fuses. This fuse block can be used withj 24-hour circuits and has a positive distribution bus with 10-32 stud. Includes a cover, which satisfies ABYCUSCG requirements for insulation. The cover incorporates an easy to open push button latch, which provides easy access to fuses. Cover includes storage for two spare fuses, and label recesses that accept Blue Sea Systems