Oyviny 4-Way Flat to 7-Way Round Trailer Wiring Adapter Black — Dual 4/7-Pin Output with Mounting Bracket

The Oyviny 4-way flat to 7-way round adapter is a vehicle-side wiring converter that gives you both a 4-pin flat and a 7-pin round trailer connection with a durable mounting bracket for easy, secure towing.

If your truck or RV has a 4-way flat socket but you need to tow trailers that use either a 4-pin or a 7-pin connector, this adapter converts the vehicle-side 4-pin wiring into a standard 7-way round plug while retaining a 4-way flat output. Built for repeated use, the adapter includes a mounting bracket, dust covers, and a protective loom so you can swap between trailers without rewiring or unstable connections.

How does this adapter let me tow trailers with different plugs?

The adapter accepts your vehicle's 4-way flat input and outputs both a 4-pin flat and a standard 7-pin round connector, enabling compatibility with older and newer trailer wiring systems. It routes the required signals through dedicated pigtails so you don’t lose braking or auxiliary functions.

• Converts 4-way vehicle socket to both 4-pin flat and 7-way round outputs.
• Includes extra pigtails for brake, reverse, and auxiliary power functions.
• Maintains standard wiring assignments to work with most trailers.

Is the Oyviny adapter built to withstand road use and weather?

Yes — the shell is molded from ABS plastic to resist rust and impacts while a black wire loom protects the cables from abrasion. Both the 7-way and 4-way sockets have dust covers to keep moisture and dirt out when not connected.

• ABS housing for corrosion resistance and impact protection.
• Protective black wire loom to guard against wear and chafing.
• Dust caps on both sockets to reduce corrosion and contamination.

How straightforward is installation and mounting?

Installation is plug-and-play for a vehicle that already has a standard 4-way flat socket: the adapter snaps into the vehicle connector and stays secure. The included mounting bracket, screws, and nuts let you fix the adapter to your hitch or frame to prevent movement and reduce wiring strain while driving.

• Plug-and-play 4-pin connection that snaps in tightly without wiggle.
• Mounting bracket and hardware included for a permanent, stable fit.
• Snug fit preserves electrical contact and prevents accidental disconnection.

What kind of wiring and conductivity does this adapter use?

Oyviny uses pure copper conductors sized to match the current demands of towing accessories: 18 AWG wire for the 4-way flat circuit and heavier 14 AWG for the additional pigtails and ground to handle brake and power signals. Solid connections and quality copper help ensure dependable lighting and auxiliary function performance.

• Pure copper wires for low-resistance, reliable conductivity.
• 18 AWG on the 4-way flat circuit; 14 AWG on pigtails and ground.
• Designed to preserve signal integrity for lights, brakes, and power.

Who this is for: The Oyviny 4-way to 7-way adapter is ideal for truck and RV owners who tow different trailers and need a durable, ready-to-install converter without running new wiring. Choose this adapter if you want a reliable plug-and-play solution with mounting hardware, dust protection, and tougher wiring for brake and auxiliary functions. It’s particularly useful for owners who alternate between utility trailers, boat trailers, and campers and need consistent electrical connections without modification.