Rockford Fosgate RFW4B 4 AWG 100-Foot Black Power Wire

The Rockford Fosgate RFW4B is a 100-foot bulk spool of 4 AWG black power wire for car-audio electrical installations. It provides the cable length needed to route power or ground wiring through a vehicle while allowing installers to cut each run to suit the system. Its full-spec 4 AWG construction is intended for installations that require properly sized cable rather than undersized wire.

This cable is suited to custom amplifier wiring, system upgrades, replacement power runs, and multi-amplifier projects where a bulk spool is more practical than a preassembled kit. The black insulated finish is useful for negative or ground-side cable routing and for installations that use color-coded wiring. Terminals, fuse holders, and other connection hardware are selected separately for the specific installation.

RFW4B uses Pure Crystal-Oxygen Free Copper (PC-OFC) conductors in a high-strand-count design. Its 1,862 copper strands support flexible routing through vehicle panels, under carpeting, and around installation obstacles. The 4 AWG conductor size has a listed cross-sectional area of 21.1 mm².

A frosted outer jacket is used to maintain flexibility while helping protect the conductor during routing. The cable is specified to meet or exceed American Wire Gauge requirements, supporting consistent wire sizing for system planning. Its black jacket provides a clean, coordinated appearance in custom wiring layouts.

Use this bulk cable as part of a complete power-delivery path matched to the amplifier, vehicle electrical system, fuse protection, and terminal hardware being installed. A 100-foot spool is especially useful when multiple cable runs or future system changes are anticipated. For a finished installation, pair it with 4 AWG-rated terminals, appropriate inline fusing, and protective loom or grommets where the cable passes through vehicle panels.

Key Features

• Full-Spec 4 AWG: Meets or exceeds AWG sizing requirements.
• PC-OFC Copper: Uses Pure Crystal-Oxygen Free Copper conductors.
• 1,862-Strand Construction: Supports flexible cable routing in vehicles.
• 21.1 mm² Area: Provides the listed 4 AWG conductor area.
• Frosted Outer Jacket: Designed for maximum cable flexibility.
• 100-Foot Bulk Spool: Allows custom-length power and ground runs.

Design & Installation

The RFW4B combines a black insulated outer jacket with a multi-strand PC-OFC copper conductor. Its frosted jacket finish and 1,862-strand construction are designed to make the cable easier to route than a less-flexible power wire. The cable has an approximately 10 mm outside diameter and a listed heat rating of 105°C.

Measure and cut each run before terminating the cable, then use connectors specifically rated for 4 AWG wire. Route cable away from sharp edges and moving or high-heat components, using grommets where it passes through metal panels. Select fuse protection, terminals, and distribution hardware according to the installed amplifier and vehicle electrical-system requirements.