Yes, it does lock sockets
598101
Lets make it clear for all the backyard mechanics who say this set does not lock sockets securely. These do!  ... As long as the user has sockets with indentations for the ball bearing to fit into, these extensions WILL lock.  If you use cheap sockets with no indents inside, do not expect the extension to lock, because it will have nothing to grab on to.  And yes, the extensions you get are not the ones pictured, but in my opinion, IMPROVED, as they have a metal knurled sliding ring that releases the socket instead of an exposed release pin.
3512775
Nicely made sockets at a fair price.convenient holder.
3117323
Yes it locks, but the wheel trays don't. Takes but 5-10 seconds to remove a bike even with the lock. Decent rack but the locking aspect is a joke.
3129590
Works perfectly. My new apartment had only gu24 2-pin sockets throughout, and I needed more flexibility with lighting. Theses solved the problem.
1816210
I bought these for my timing chain project on my Mini. Sockets fit snug, no flash or tool marks noticed. The smaller sockets are slightly tough to remove from the rubber carrier.  Carrier is good at holding the sockets together.  Non have fallen out. Used with Craftsman ratchets and torque wrench.
4654446
The socket layout is reasonable. Time will tell as to if its an effective protection against surges and spikes
2104038
It locks when I ask it to, it also unlocks when needed. Easy to install and integrate with my alarm...
4051709
I have had one of these a while back but lost it during moving. I never had a problem with it. It works fine and  the rotating sockets are very convenient.
1817076
I thought that you could use the appliance while this thing created a snug fit... we live in an old house an it has loose sockets... and it holds in place, but blocks electricity from getting to the appliance. This product is similar to the socket protectors, but with holes in them.
664495
I'm sure I can use sockets but this makes things so much easier and in my opinion well worth the money.
2344448
So nice to only keep track of one socket versus two. Socket works on 2016 isuzu npr truck like a charm. Just ensure you aren't engaging the bud stud when removing the lug nut. But it is simple enough that a kid could use it.
1936954
I was recently trying to do some at home repair on my car. I have a travel socket set that I was using, but it was difficult to tighten the bolts manually as much as I wanted to. I found this at just the right time. I used the power drill attachment to tighten the bolts as tight as they were originally. It fit onto my 8mm bolts without issue. This can me used for basically anything that has some sort of raised edge. This is now the only socket I carry around and usually keep it in my power drill case. It feels heavy and well made. This is a tool I would continue to recommend to family and friends.

Disclaimer: I received this product at a discount for my honest and unbiased opinion and review.
3023715
I bought this to replace the doorbell transformer that I'd disconnected when rewiring something else.  It has a screw to prevent it from falling out of the socket.
2389508
Works well, just wished it had a led on the inside to tell you if it is locked or not.
4759658
Works just like it says and seems to be good quality. It's a little longer than a standard socket because of the dual female design but it will still fit in a standard outlet/plug box. If they have some that are a little deeper then they'd be ideal, but this is still a solid solution. Great for a flexible, removable/non-permenant solution. No need to strip and connect wires to an integrated socket. Just connect two plain Ethernet cords at the wall.
3923902
Does a great job hiding the mounds of wire that comes with having a computer, stereo, etc.  My only complaint is that the "concealment door" doesn't like to stay shut when when every socket is used.
373197
these extensions are solid enough, and they have a ball-style lock to hold the socket on, but they do not have the indentations to allow them to hold tightly on to the anvil of your ratchet. a very simple thing that is often taken for granted.