I used this block on a pinned barrel that prohibited normal gas block installation, set it up with a MI drop in hand guard. I have fired many hundreds of rounds and the screws are still tight (red locktite) and the rifle has not had a malfunction. The block and sight are as well made and should perform for years.

Bought this to get standard A2 front sight out of my scope's view (2.5 power Kahles)after reviewing other reviews.
Easy enough installation after removal of pinned front sight assembly but required a good deal of time and 2 boxes of ammo to get it to function properly as when front sight was in perfect alignment with rear sight and center plane of barrel (and gas block against the grip plate)the gas holes in the barrel and the front sight clamp did not align. After repeated loosening, tightening and firing gun now fires reliably but
when raised the front sight is canted noticeably off-center. Its not my primary sight or my nicest AR so not a huge deal, but a perfect fit would have been nice - also, the small attaching screws will not stand up to much torque (7/64 hex heads are easy to 'round out').

Had my forged front sigh assembly removed and put this bad boy on. Love it. The release button that allows you to collapse it can be a little stubborn and install was a little complicated on my patrol rifle because I have a pinned compensator. My dept armorer installed it and had to cut the old sight assembly off but this is only an issue if your compensator is pinned.

Installed this on a customers rifle and was pleased with it. I prefer a block with set screws as opposed to a clamp on style but have not had any problems. Would also be nice if the sight was spring loaded. However, this sight was very solid. The rifle functions just fine and i havent had any issues with the block moving out of alignment

New AR build... Great quality and price.

another great product from Yankee hill. looks great. easy to install and very solid. I highly doubt the screws would ever back out but just to be sure I used some loctite on them. the sight is easy to deploy and locks in place very solidly. so far its made people with a standard A2 gas block very envious.

great fit on my s&w m&p-15x. 50 rounds later it ran like a top. only reason it dosent get 5 stars is the fact that its hard to get it exactly level so its not canted because it has only the 2 straps w/ skrews. they should have out ridges on the bottom of the barrel straps to fit into the the cutouts for the front sight pins in the barrel. so it would auto level itself. something you think a company like yhm could figure out, but whatever. also the push button and locking mechanism seems like it could have been made better. but it works ok

This product from YHM is very well made. I will look for that company when purchasing other upgrade/replacement parts for my ar-15. One cool thing about this sight is that when it is flipped down it is exactly flat across the top with my top hand guard rail.

Great product from YHM. Works as described, and looks good while its doing it!

For the price, you can't beat it. Easy to install and with the option of getting it without the bayonet lug, lets you do some modifications to your rifle without breaking any laws, depending on where you live ofcourse.

For the money, you can't beat it! Not only is it a flip sight, but it is a gas block. If you are putting flip sights on your rifle, then they are most likely back-up sights. These sights are well-made (American made) and accurate. Well worth it and easy to install. The biggest requirement is a little patience in assuring that it is lined up perfectly.

I ended up getting this one because the option with the rail on the bottom was sold out or on really long backorder.

When you flip the sight up, there is absolutely NO play. You can definitely have confidence in this sight and depend on it maintaining zero. My only complaint is that I felt the set screws were a little small and I thought I wasn't getting enough torque on them. I did apply Locktite and hopefully they stay tight when the barrel heats up.

Oh and one more thing. If you are using a free floating hand guard, you need to make sure that it falls short of the gas block. You will have to install the forearm first, then you will have to install this.

Had a cycling problem with my M4 SBR. Switched to YHM gas block and now I'm ripping rounds down range.

EVERYTHING ABOUT THE WAY THE SIGHT DEPLOYS AND RETRACTS IS EASY ONE HAND OPERATION. I BOUGHT THIS SIGHT FOR MY RIFLE AND HAVE PUT 3 MORE ON FRIENDS OF MINE. WHEN INSTALLING, YOU DO HAVE TO SPEND A LITTLE TIME IN THE ALIGNMENT OF THE SIGHT SINCE IT IS NOT PINNED, BUT I HAVE YET TO RE-ADJUST ANY THAT I HAVE PUT ON. IT JUST TAKES A GOOD EYE. MINE HAS BEEN ON MY RIFLE FOR ABOUT 2 YEARS NOW, AND THERE IS NO SLACK OF ANY KIND. IT'S EXTREMELY TOUGH. THE RAIL IS A PLUS ALSO. THE SAME LIGHT ON YOUR HANDGUN WILL SLIDE RIGHT ON AND IS EASY TO USE WITH YOUR OFFHAND ON THE FORE GRIP. I LOVE IT.

This is a solid block that installs fairly easily and works well. The sight is sturdy and locks positively in the "up" position. I've put two of these on uppers.

I would have given it 5 stars if Yankee Hill included some sort of metal shim that properly spaces the block for installation without a handguard cap.

Very easy to instal, well made and when folded down mounts flush

eazy to install,and works great for backup to optics,if they go out.im a ofc,and the sight came into play just at the right time and i will always use them.i have two ar m4 carbines and they are on both guns.

I ordered this sight to replace a broken one on an older barrel I had with a permanently attached flashhider. I was reluctant to use or try a front sight/ gas block that was a clamp on design but I must admit once installed it fits and performs excellent. It has given a custom look and breathed new life into an otherwise plain barrel. I would recommend this item and buy one again for antoher project.

Have purchased and installed 2 of these. The first one has been on for about 2 years and the second about 8 months. Both guns get regular use and have not had any problems.

Well made and a great price compared to similiar products from other companies.

I used this gas block on a a project rifle I wanted to trick out by myself. The hardest part of the entire install was removing the front sight tower pins from the original sight. Remove the old, line up the new, and a little red locktite and you're done. The sight deploys easy and locks up. It's not a con, but plan ahead. Since the sight is part of the gas block, if you someday plan to upgrade to a gas piston you'll need to buy another sight to go with.

Easy to install. Functions perfectly and looks awesome.

I use this product strictly as backup to my optics. Superior construction, and highly recommended. Easy to install, and good looking to boot.

This was the perfect addition to my AR variant build. It goes on in a snap and stays put. It holds a zero and take standard front sight posts. I changed out the FSP for a thinner diameter one.

Outstanding fit and finish. Front sight has zero movement when in the up position, and locks securely in the down position. Very accurate!

Very high quality piece. Looks as good as it works! Folds low and completely out of the way for optics. Locks into position when up, no lock when folded... though i have not found that to be an issue. Excellent when added with my Samson Star-C Rail.

After purchase of several YHM components, I've found them to have a reputation for good parts. This flip up sight gas block is no exception. The flip sight is easy to deploy, and once up and the cross pin engaged, the sight is in place tightly. In the down position, the sight is about the same height as the railed forend on the carbine. The sight height aligns with an A2 carry handle nicely.

This sight was easy to install and comes with the front sight post and detent installed. Alligning it takes a little care, but I've installed two of these so far and both rifles ran great. Plus it's less expensive than other models. The railed model might be alittle heavier than some the other two, but that integral rail is a nice accessory.