Overview

The Blue Sea Systems 7870 is a black 180-label set for DC circuit identification on emergency-vehicle style electrical systems that use compatible ST Blade fuse blocks. Each label measures 0.625 x 0.375 in. (15.88 x 9.53 mm), and the label stock is reinforced and weatherproof for service areas where panels and fuse blocks see regular handling.

This set is a practical fit when you want readable circuit names right at the fuse block instead of relying on handwritten markings. For marine installations, the main checks are straightforward: the fuse block needs to be one of the compatible ST Blade models, and the printed label names need to match the way the onboard accessory circuits are actually laid out.

Key features

• 180 DC labels in one set for auxiliary distribution layouts with many branch circuits
• Small-format label size of 0.625 x 0.375 in. (15.88 x 9.53 mm)
• Reinforced, weatherproof material for fuse blocks mounted in damp or exposed service areas
• Made for Blue Sea Systems ST Blade fuse blocks
• Fits compatible ST Blade models including 5023, 5025, 5026, 5028, 5029, 5032, 5035, 5045, and 5046
• Keeps circuit identification at the fuse block clear during troubleshooting, fuse replacement, and later service work

Compatibility and fit

This label set matches Blue Sea small-format label recesses used on compatible ST Blade fuse block covers and related layouts in the same family. It is not a universal panel label sheet, so physical fit is tied to the fuse block style rather than just the label wording.

The other fit point is the circuit naming itself. Because this set is arranged for emergency-vehicle use, it makes the most sense where the vessel or special-purpose craft uses the same terminology for its DC accessory circuits.

Installation and use

Installation is simple on the correct fuse block because the label size matches the recess format used by compatible ST Blade units. Once applied, the labels give each fused branch circuit a fixed reference point on the block cover, which is useful when several added loads are grouped in one distribution area.

This is a good match for patrol boats, support craft, and refit projects that borrow emergency-response circuit naming. For a standard cruising or fishing boat, it is worth checking the printed legends against the actual onboard load list before ordering.