CURT 4-Way to 7-Way RV Blade Adapter 57672 — Dual-Output Black with Mounting Bracket & Dust Covers

The CURT 57672 is a dual-output adapter that converts a vehicle's 4-way flat socket into both a 4-way flat and a 7-way RV blade connector for towing multiple trailer types.

This compact electrical adapter lets you quickly bridge the gap between mismatched trailer and vehicle connectors without replacing your factory wiring. Designed for common towing setups, it gives trucks and SUVs the flexibility to run basic lighting circuits or the fuller set of signals and auxiliary power a 7-way blade provides. The assembly includes protective dust covers, a mounting bracket and hardware, plus a slit loom sleeve to keep wiring neat and shielded from the elements.

How does this adapter let me tow different trailers?

The CURT 57672 creates two outputs from a single 4-way vehicle socket: a pass-through 4-way flat and a converted 7-way RV blade. That means you can plug in a simple lighting-only trailer or a larger trailer that needs brake control and auxiliary power without swapping connectors.

• Converts a vehicle 4-way flat into both 4-pin and 7-pin outputs
• Supports taillights, brake lights and turn signals via the 4-way
• Enables reverse lights, trailer brakes and auxiliary circuits via the 7-way (some splicing)
• Includes mounting bracket for secure attachment at the hitch or bumper

What protection does it offer against water and corrosion?

Weather resistance is built into the design: dust covers keep moisture and dirt away from both sockets when not in use, and the included slit loom sleeve organizes and shields exposed wires. The housing is made from resilient black plastic that won’t rust, extending service life in outdoor and towing environments.

• Dust covers for both 4-pin and 7-pin sockets
• Slit loom sleeve protects wiring from abrasion and road debris
• Durable plastic housing resists corrosion and environmental wear
• Mounting hardware keeps the adapter stable and reduces strain on connections

How difficult is installation and will I need to rewire anything?

Installation is straightforward for most users: the adapter plugs into a standard 4-way flat socket and supplies the additional 7-way blade output. Some trailers and brake controllers require manual splicing or a short run of wire to match additional circuits, but the included bracket and hardware simplify a tidy, secure install.

• Plugs into any standard 4-way flat vehicle socket
• Minimal splicing may be needed for brakes, reverse, or auxiliary circuits
• Comes with mounting bracket and all necessary hardware
• Clear wiring layout helps reduce installation time

Will this work with my truck’s braking or auxiliary systems?

The 7-way output provides the extra pins needed for trailer brakes and auxiliary power, but these functions depend on your vehicle’s wiring and any brake controller. If those circuits are not already present at the 4-way feed, you may need to run additional wiring or use a compatible brake controller to enable them.

• 7-way output includes pins for electric brakes and auxiliary power
• Requires proper vehicle-side circuits or added wiring for full functionality
• Works with standard brake controllers when wired correctly
• Ideal for adding trailer features without changing the vehicle harness

Who is this for: The CURT 57672 is ideal for drivers who tow a mix of trailers — from simple utility trailers to RVs or equipment trailers that require added circuits. It’s a practical choice for DIY installers, fleet vehicles, and occasional haulers who want a durable, weather-resistant way to expand a 4-way flat socket into a 7-way blade while preserving the original 4-way connection.