Rockford Fosgate RFD4 4 AWG Distribution Block

4 AWG Distribution Block 1 Input (1/0 or 4 AWG), 3 Outputs (4 or 8 AWG), Removable Gauge Adapter Rings. Custom Tooled Solid Brass, HPP Platinum Finish.

Product Overview

The Rockford Fosgate RFD4 is a 4 AWG distribution block with one input and three outputs, featuring removable interior adapter rings that allow the terminal openings to be adjusted for different wire gauges. The input accepts either 1/0 AWG or 4 AWG wire; each of the three outputs accepts either 4 AWG or 8 AWG wire. This flexibility makes the RFD4 suitable for distributing power from a main 1/0 AWG or 4 AWG run to three smaller-gauge output cables serving individual amplifiers or accessories. Constructed from custom-tooled solid brass with HPP platinum finish.

Key Specifications

• Part number: RFD4
• Configuration: 1 input / 3 outputs
• Input wire sizes: 1/0 AWG or 4 AWG ✓
• Output wire sizes: 4 AWG or 8 AWG per output ✓
• Gauge adjustment: Removable interior adapter rings ✓
• Construction: Custom tooled solid brass ✓
• Plating: HPP (High Performance Plating) — platinum finish ✓
• Corrosion resistance: Superior (HPP confirmed) ✓
• Terminal type: Not specified — confirm with Rockford Fosgate
• Current rating: Not specified — confirm with Rockford Fosgate
• Mounting: Not specified — confirm with Rockford Fosgate
• Dimensions: Not specified
• Weight: Not specified
• Warranty: Not specified

Features & Benefits

• 1 In / 3 Out Configuration — Splits one main power or ground cable into three independent output runs — suitable for distributing power to three amplifiers or accessories from a single main supply cable.
• Removable Interior Adapter Rings — Multi-Gauge Flexibility — Removable adapter rings inside the terminal openings allow the output ports to accept either 4 AWG or 8 AWG wire depending on which ring is installed. This allows the same block to serve installations with different wire gauges across the three outputs without requiring separate distribution blocks.
• 1/0 AWG or 4 AWG Input — The input accommodates both 1/0 AWG (for high-power main runs) and 4 AWG (for medium-power main runs), allowing the RFD4 to serve at different points in a power distribution chain.
• Custom Tooled Solid Brass — Machined from solid brass for high current capacity, precise tolerances, and long-term mechanical reliability.
• HPP Platinum Plating — Corrosion-resistant coating maintaining low contact resistance at all terminals over time.

Technical Specs

Compatible With / Goes Well With

Suitable for:

• Distributing a 4 AWG main run to three smaller amplifiers or accessories
• Secondary distribution from a 1/0 AWG main run (with RFD1 as primary block)
• Multi-amplifier and multi-accessory systems requiring three 4 AWG or 8 AWG output branches

Pairs well with:

• Rockford Fosgate RFD1 (1/0 AWG primary distribution) as a secondary block
• Rockford Fosgate 4 AWG and 8 AWG wire runs
• RFT4 / RFTS4 ring terminals for 4 AWG output connections

Frequently Asked Questions

How do the removable adapter rings work?

The interior adapter rings are removable inserts that line the terminal openings. With the 4 AWG ring installed, the port accepts 4 AWG wire; removing it allows the larger opening to accept 8 AWG wire (or vice versa — confirm the exact adapter ring operation from the official Rockford Fosgate RFD4 product page, as the description may indicate rings reduce rather than enlarge the opening).

What is the difference between the RFD4 and RFD1?

The RFD1 is a 1-in 2-out block accepting 1/0 AWG or 4 AWG on all ports. The RFD4 is a 1-in 3-out block with 1/0 AWG or 4 AWG input and 4 AWG or 8 AWG outputs — with removable adapter rings for gauge flexibility. The RFD4 is better suited for distributing to three lighter-gauge output runs.

What is the maximum current capacity of the RFD4?

Not confirmed in the supplier data. The solid brass construction with 1/0 AWG input capability indicates a high-current design — confirm the rated current from the official Rockford Fosgate RFD4 product page.

How is the RFD4 mounted?

Mounting method not specified. Confirm from the official product page.

Can the RFD4 be used for ground runs?

Yes — a distribution block functions equally for positive (power) and negative (ground) runs, provided all terminals are connected to the same polarity.