Mul-T-LockMT5+ Hercular Single Cylinder deadbolt w/Thumb Turn - Satin Chrome

I'm a retired Police Officer, and in my opinion, these are the best deadbolts on the market. They are made very well and unless your are a locksmith, they are not going to be picked. They cannot be bumped and no one can duplicate the key unless they have the key card that comes with it. The ball bearing in the throw bolt feature makes these one of the most secure deadbolts out there. You cannot get past it without busting the strike box completely off of the door jamb, which won't be easy if you use the 3" screws. If the lock doesn't deter the burglar all together, it'll definitely hinder their plans of quietly breaking into a house. Nothing if completely burglar proof, but this will help make your home as good as it gets. These deadbolts will definitely stall someone from trying to bust in through the door. If you have a window on the door, or a window near the door, make sure to use a security screen to keep someone from just breaking the glass and reaching in and unlatching the deadbolt from the inside.The locks operate very smoothly. I got them for a new home because who knows how many copies of the keys to the existing locksare out there when you buy a previously occupied home?

After hours of watching videos and researching dead bolts, I hit the purchase button on this one. Build quality is top of the line. Very heavy and you can tell it's made right. The only thing they should have done differently is use stainless screws. I had to replace the long screws because they got chewed up after fitting the strike so many times. Install isn't so easy unless your frame was prepped for this lock. The strike is boxed in to capture a pair of ball bearings that project out from the bolt, locking the bolt into the strike. You aren't going to smash through this setup without a bulldozer but it makes install much more complicated. This door is framed by metal in a 12" concrete tornado shelter wall. I had to cut the hole with a grinder and file to size for the strike. Once the opening was about right, I used a straight grinder with a router bit to deepen the hole so the strike would go in all the way. It took about 90 minutes to fit everything and I had a pile of tools to put away, but it was worth the effort. The lock set strike is a home made job of 1/8" steel bar. It's not the prettiest, but that's not my primary concern. After everything was tested, I filled the entire frame with great stuff door foam. It shot out of every crack and crevice telling me the frame was completely welded to the concrete wall. I hope to never have to use this shelter but if I do, the door and locks aren't what's going to fail.

Very expensive lock! So, you would expect perfection. However, first lock I got had a broken piece. The replacement lock came with a missing a clip. I WILL NOT PURCHASE ANOTHER DEABOLT FROM MUL-T-LOCK! This is ridiculous!

I know that sounds like a fake title, but its true. I have had to contact the seller twice and both times they have helped including sending me new screws that were lost during installation. Locks are heavy duty. Very happy with them.

This Mul-T-Lock MT5+ should be called Mighty Lock. Heavier and stronger lock AND hardware outclass anything else I've seen. Installation into existing deadbolt holes was delightfully simple. It adjusts without fuss to the two standard US predrilled setups using included directions.Plus you cannot get keys duplicated without your own key card. (Don't lose it )Big upgrade on security and heft with this deadbolt. I'm impressed.

Heavy duty, good looking deadbolt for exterior door. The product came complete, in brand-new condition.

Amazon is making me pay to return. Not happy with this

The lock is adjustable for the two most common sizes. It fit on my new iron security door.