Overall this is a great set of matching gun locks. You will receive in the package 3 locks, keyed alike, with 6 matching keys. For me, this is the perfect set. I use one for my Mossberg 500, one for my wife's Smith & Wesson Bodyguard .38 special, and the other is for my Glock 17. The fit for the Mossberg and Smith & Wesson is great and installation is easy. Seat the lock against the trigger guard, making sure the metal of the trigger guard is between the crescent shaped black plastic ridges inside the lock (see photo). If it doesn't fit, you probably have the lock on backwards, switch sides and try again. The trigger guard should fit between the plastic ridges which stabilizes the lock when seated and secured. The only trick is you need to squeeze very tightly when seating the lock. Since the pads on each side of the lock are rubber, you can squeeze tightly to compress the rubber against your trigger guard and get a tight fit. Again, for the Mossberg and the S&W with thin metal trigger guards the fit is a breeze. As far as the locking mechanism itself, it is smooth to turn, key insertion is easy, you can tell (as with most Master Lock products) that the lock is well built and should last long with repeated use. The key and lock internals look to be brass or brass alloy, which should help hold up well over time.For my trusty Glock, the fit is not so easy. Seeing as I have a Glock 17, chambered in 9mm, and the fit is very tight, I am not sure this will work with larger caliber Glocks. When securing my Glock, the plastic ridges I mentioned above do not engage with the thick plastic trigger guard of the glock. The lock fits but needs to be seated very carefully and you need to use a lot of pressure squeezing the two sides of the lock together against the trigger guard to even get this lock to engage. It just barely fits. If you plan on putting the lock on your Glock and then storing your Glock inside the black plastic Glock brand gun case you may be disappointed. The overall thickness of the lock on the gun will not fit well in the Glock case, with mine it caused the sides of the case to bulge out and I decided against using that lock/case combination to avoid damaging the case over time with repeated use. Again, that is my experience, ymmv.BOTTOM LINE: Great price, solid well built locks and keys that are a great safety accessory for owners of multiple guns. I know my review only spoke to the compatability and 'ease of use', but the lock really feels well built, solid construction. The finish on the outside of the lock is like a steel blue (silver blue) and it looks to be a powder coat or enamel finish. Looks good, works good, ties the whole gun collection together like Lebowski's rug did to the room. Having multiple locks with multiple matching keys makes life easy for me. My only caveat is the varied fit you will find with polymer framed guns that have thicker/wider trigger guards, again ymmv.

Obviously I have hand guns and more than a few....Now that's out of the way! All I can say is that even with a safe, I have found that trigger locks provide great peace of mind in preventing unauthorized people from using your firearm. These master keyed "Master Locks" work extremely well and fit all my firearms. I would highly recommend purchasing these locks. I know there are some that don't like to use these locks and I wouldn't recommend this lock if your intention is to keep your home defense firearm locked with the hopes of unlocking it if or when someone is breaking into your house. If that's your thought then I would highly suggest that you rethink that position and I would say this product is not for you. But if you have several firearms and you are going to put them up or store them. Then this is an extra level of security assuming that you are using a safe. Anyway, this is a solid product that is very very easy to use.

Lost my keys and had one in use. Had to drill the lock off (talked to a locksmith and that is what he said he'd have to do). Of note, I drilled part of my trigger off as well to get it off. manufacturer covered it even when I explained that it was my fault, H is a great company! Now I have 3 that are keyed alike and they are easy to put on and very sturdy. 1 key on me and the others at home. A good price too.

I bought these trigger guards for my handgun and shotgun. I have cable locks and trigger guards through both my guns- I know it's overkill but that's my preference. Anyway, these locks are great! There are 6 keys so you can have one on multiple key chains and hidden locations. And all the keys work on all the locks. Excellent.Unlike some of the other reviewers, I've never been able to tamper with them and open them with a pick. Though to be honest, your guns should never be so exposed as to have a thief bring a lock-picking set specifically to open your trigger locks.The locks have hard rubber, pyramidal teeth to grip the trigger housing and prevent much movement. There are also pins that expand and contract to supposedly surround the inside and outside of the trigger guard to also prevent movement. But a lot of the rigidity of the lock is in the strength of the compression you secure the lock. If you gently close the two halves together and lock it, yeah there will be play. If you firmly press the two together and lock it, there will be little to no wiggle room. If you give it the vulcan death grip, its not going anywhere!My only- ONLY complaint with these locks is that they stick out too far. I get that they are supposed to accommodate a wide range of makes/models/customizations of guns, but that nub you see sticking out in the pictures, is kind of long. It's a hassle to put/find a case for my handgun and even more of an issue for my shotgun. I had to settle for a scabbard carrying case for my shotgun which barely provides clearance. I'd say they are maybe...1 1/2" - 2" long? I can't think of any workaround (engineering wise) for the length. I'm sure if they made this shorter, more people would have issue with compatibility with their guns.Overall a worthy product. Many locks, same key. Keys all universal with the provided locks. Good price!

They are functional on my pellet guns.

great for what I needed, arrived in good time and do the job!

The Master brand of gun locks is better quality than the other brands that look like them. I buy the 3 - packs of keyed alike for the convenience of having one key for any of the locks in the set. You also get 6 of the same key so you'll have extras in case of loss.

They seem to function fine. No complaints. Cheaper than Master brand.

Having a 3 pack of locks keyed alike are great to reduce the amount of keys you need. One complaint is that you may need graphite powder to help cause some of the locks/keys I received didn't work as smoothly as others.