Master Lock Keyed Alike Universal Trailer Coupler Locks 379KA-6 - Six

In this review the Master Lock 379KA-6 six pack is judged on convenience and security for owners who need multiple trailer locks that operate with a single key. The bottom line: this set is for someone managing several trailers, carts or equipment who values fast, keyed-alike access and a stout, simple design that resists common blunt-force attacks. Each lock ships with two keys, and the set's keyed-alike feature makes daily use and key management noticeably easier than juggling different locks.

Key Features

• Six locks keyed alike: All six locks open with the same key, removing the need to carry multiple keys when using several trailers or attachments.
• Two keys per lock: Each lock includes two keys so the six pack supplies a total of twelve keys for shared access or backups.
• Universal fit: The design fits 1-7/8 in, 2 in and most 2-5/16 in couplers from common manufacturers, covering a wide range of trailer tongues.
• Sturdy zinc alloy body: Reinforced zinc die-cast construction resists rust and offers impact resistance better than many lighter materials.
• Anti-blunt force design: When locked the body rests on top of the coupler and can rotate slightly, making downward hammer strikes and sledge attacks harder to execute.
• Rekeyable cylinder: The lock uses an advanced cylinder that resists picking and can be rekeyed if desired for long-term convenience.

Who It's For

This pack suits fleet owners, contractors, or recreational users who manage multiple trailers, boats or equipment and want the convenience of a single key for all coupler locks. It is especially useful when trailers are stored unattended or left at a jobsite where basic theft deterrence is needed.

It is less appropriate for someone who needs custom master keying across separate orders, since ordering multiple six-packs will not automatically produce the same key code. Buyers seeking ultra-high security hardened steel couplers or electronic locks should look elsewhere.

Pros & Cons

Pros

• Keyed-alike convenience reduces key clutter and speeds hookup for multiple trailers.
• Two keys per lock provide immediate backups or spare distribution.
• Design and zinc die-cast body resist corrosion and blunt-force attacks better than lightweight alternatives.
• Universal fit covers the most common coupler sizes and many major manufacturers.

Cons

• Ordering multiple six-packs does not guarantee identical keys unless purchased keyed alike through the merchant, which adds complexity for larger fleets.
• Some customers report mixed impressions of build toughness, so extreme heavy-duty environments may require a different lock type.

Specifications

Package contents	Six keyed-alike coupler locks with two keys each (12 keys)
Compatible coupler sizes	1-7/8 in, 2 in, and most 2-5/16 in
Construction	Reinforced zinc die-cast body
Lock type	Rekeyable keyed-alike cylinder
Weight per lock	Approximately 2.4 lbs
Warranty	Limited lifetime warranty

Our Verdict

The Master Lock 379KA-6 six pack is a practical, good-value solution for anyone who needs multiple trailer coupler locks that work with a single key. It balances convenience and basic theft deterrence through a universal fit, solid zinc construction and an anti-blunt-force design, making it a strong choice for fleet managers and recreational users, provided they confirm keyed-alike ordering for larger quantities.

Frequently Asked Questions

Will the same key open all six locks?
Yes, the six-pack ships keyed alike so one key opens all six locks out of the box.

Do these locks fit my coupler?
They are made to fit 1-7/8 in, 2 in and most 2-5/16 in couplers from many common manufacturers.

Can I get more locks keyed the same?
Ordering multiple six-packs does not guarantee identical keys automatically; contact the merchant for larger keyed-alike orders.