Blue Sea Systems ST Glass 6 Circuit Fuse Block with Cover

The Blue Sea Systems ST Glass 6 Circuit Fuse Block consolidates up to six branch circuits behind traditional 3AG glass fuses — AGC fast-acting or MDL time-delay — in one compact, labeled block. It's a straightforward, economical way to add circuit protection without a full breaker panel.

Key features

• 100A total, 30A per circuit, 32V DC maximum
• Tin-plated copper buses and phosphor bronze fuse clips
• Clear insulating cover with spare-fuse storage and large-format label recesses
• Accepts AGC, MDL, and all other 3AG glass fuses (sold separately)

This version has no integrated negative bus — pair it with a separate ground terminal block, or step up to PN 5015, the same block with a built-in negative bus, if consolidating grounds in one place is a priority. Both mount with #10 screws and use the same #8-32 screw terminals.

Glass 3AG fuses are a legacy standard still common on older boats and in panel replacement work, so this block is a frequent choice when matching existing wiring rather than converting a boat to ATO/ATC blade fuses. Keep a small stock of AGC and MDL fuses in the amperages your circuits use, since the block's cover only stores two spares at a time. Because it shares the same footprint and #10 screw mounting as PN 5015, you can swap between the two if your grounding plan changes mid-installation, without re-cutting the mounting surface. Torque the #10 mounting screws snugly but don't overtighten into the reinforced polycarbonate base, which can crack under excessive force.