Prime-Line U 9809 Sliding Window Lock for Vinyl Windows – Easy Installation to Keep Windows Securely Closed – Diecast Construction, White (2 Pack)

These window locks have definitely earned my anxiety’s seal of approval! They work incredibly well and bring me that extra bit of security I was looking for. Ignore the scratches in my pictures—one of them fell off, and my dog (she decided it was her new chew toy) went to town on it. Thankfully, they’ve held up great despite the “extra testing.” They’re super easy to twist on and off, making it simple to open and close the windows. The only slight annoyance? You do have to twist them all the way to adjust the window, which makes sense for security, but can be a bit of a pain when you just want a quick crack of fresh air after overcooking something! One bonus I appreciate is that they’re just tricky enough to keep my child puzzled, which adds that extra layer of peace of mind. I’ve got these on all our windows, and I’d highly recommend them to anyone needing a little extra home security (or pet durability)!

These window locks work great! Easy to set up and remove too.

You'd hear someone trying to get in with these installed. The latch allows for quick removal in an emergency unlike some of the others that require a hex tool.

After being burglarized years ago, I’ve always been super concerned about home security. One of the challenges I’ve struggled with is a window unit air conditioner installed in a window that opens vertically. My initial thought was to drill a hole through the frame of the window and put a piece of metal through the hole to secure it so it could not be opened more.. that wasn’t going to work because vinyl windows don’t have a metal frame. They have a vinyl frame and I don’t want to put a hole through it. The type of air conditioning unit I have only requires that the window be open about 6 inches if that so even if a criminal wanted to break in as long as the window won’t go up, they’re going to have a hard time of it. I put a clamp on either side, securing it in place and had my male neighbor come over and told him to give it his best try at opening it. He couldn’t. A burglars only choice would be to actually break the window and at that point, the burglar has a lot of of other choices that will be hard and noisy. Let’s face it. A determined crook is going to get in, but the harder you make it the more likely they’re going to move along. I now have these installed on all of my windows and provided that you screw them tight and really push down the lever that clamps it in. I don’t think they’re going anywhere. And also, because all of my windows are planted with shrubs underneath with stickers crooks are not going to spend a whole lot of time trying to access that way without regretting it.

The best window stopper. This one is worthy.

Looks like they are made well, not plastic. 5 stars for quality, minus 2 stars because they don't fit my vinyl sliding windows, because there is a thin lip that would crushed if this lock is used and tightened.

My rental house has new Anderson double horizontal siding windows. I don't have central air, so I wanted to be able to leave some windows open while I am gone working during the day so it's not an oven when I return. Also I just installed a portable AC unit in the bedroom. These work exactly as advertised and are very simple. I would point out two things: 1) you need two per window if you are using them to secure partially open windows. With just one, you can knock it off by closing the window a bit and then ramming it against the lock. Reviewers with vertical sliding windows put one on each side but for the horizontal windows you'll want to put two next to each other. Other reviewers mentioned using 3m sticky shelf liners to prevent a single one from being defeated, but I haven't tried that. 2) if you have dual sliding windows, these will only lock the inner window. If the normal locking mechanism is the type that binds one window to the other in the center, then these are not a complete security solution, as the outer window can still slide freely. I added the outer window stick-on devices that you can popout-to-lock / fold-in-to-slide to complete the solution.

The window lock in my office has never worked. I was skeptical about these locks until I got them in the right position and tightened them on both sides. These do the job well.

Terrible, didn’t work to secure the sliding windows, then straight into bin unfortunately. Don’t recommend

Great for stopping lower sash from being raised but obviously doesn't stop upper ( rear) sash being lowered! Still looking for a solution to this which doesn't involve drilling into the frame.

extra strength for your front door

Funciona muy bien para asegurarlas ventanas y el material se siente resistente. Lo volveré a pedir para otras

Perfect for controlling and securing the windows. They came assembled and ready to use. The cam-lock was especially intuitive for a cyclist as they are much like my front and rear axles. I know how I trust my wheels to stay put so do I trust these quality cam-locks to perform. Great product and will recommend to family and friends. Thank you Prime Line Products!