Artoshin 1 Pack Window Security Bar Adjustable Sliding Lock Security Stick for Rubber Tips, Adjustable Sliding Glass Door Lock Bars 15.7''-27.5'' Tension Rods 1.2'' Diameter Window Safety Lock Bar

These were perfect for my needs! The fact that they are adjustable assured a perfect fit for all of my windows. They fit easily inside all of my frames. I would definitely buy these again!

Using it to keep a window from being opened that has an air conditioner, it hasn't slipped all summer and seems to be hard to bypass if someone wanted to try to get in.

So far, these work great for our sliding windows (ugh, srsly), but they do seem to lose some of their strength if you need to open them wider than about 32" or so. Above that, they seem to have a bit of give. I'm not going to test it by trying to break into my house (and honestly, most people would probably just break the glass anyway), but it would at least slow someone down a bit, and that's what matters.

These add peace of mind, fit my window, and are easy to remove when I want to. They are non-obtrusive looking as well. Really happy!

The diameter was huge. More like curtain rod

Works as expected! Easy to use.

I purchased this to keep the windows down against aircons. It works well though I could have ordered a model that is shorter in total length. Remember you don't have to keep a lot of tension against the window when installing. ;)

These appeared to be well made, nice looking, and sturdy. Unfortunately, the size totally compressed was 16.5, not 15.7 or even 16.0. My opening is 15.8 to 16, so I could not use them.