Prime-Line U 9921 Adjustable 28-48 Inch White Aluminum Window Security Bar Lock (Single Pack) - Sliding Door & Window Safety for Home & Apartment Protection

Congratulations if you're right now thinking about securing your ground-level sliding doors with this product. With the standard locks on these doors you can easily break them open with a crowbar. The screws and the flimsy construction of the locking mechanism will just break and it won't even make a lot of noise. (Just to clarify - I'm not in this kind of business, but it's obvious). This lock bar will mechanically prevent the door from being opened.For installation you need: It comes with the 5 screws you need but you will also need a power drill with a metal driller (you can get a driller set at a Home Depot for under $5). And a Phillips screwdriver.How long will it take: About 10-15 minutes, I'd say mediocre complicated. The hardest part is to screw the holes in the metal so that they will exactly fit, and then the part where you need to screw in the screw close to the glass. I messed up at least one screw each time, so my tip is: don't make the holes too tight and make sure they are exactly in place. Good luck, don't drill into the glass!How effective is it: On an inside-slider very secure, on an outside-slider okay secure but definitely an improvement (an inside slider is a patio door where the sliding part is sliding on the inside/inside the room vs. the outside slider where the moving part is outdoor). Reason: On the inside-slider the bar simply blocks the movement like a peace of wood etc would do, while on the outside-slider the pressure is on the saddle that holds the "head" of the bar (look at the images I have uploaded).The quality: Well, could be better but is good enough for the money. The whole construction is a little bit flimsy and with some pressure the bar is bending a little bit, but I assume it won't break and the amount of movement someone could apply from the outside is limited anyway.Three great things the manufacturer is not even providing with the product description:1. The saddle has a plastic layer that makes the head snap into it (which is important so nobody can easily lift the bar with a wire from the outside).2. When lifted the bar snaps into the bracket, meaning it will stay up (lock in the upright position). While this is a little bit wobbly it's better than the bar hanging down.3. The locking lever is flexible, so you can pull out the bar (make it longer) but when pushed back in the lever will block the bar unless you press it down. With an inside slider you can leave the door open an inch for venting with the bar locking it at any position. That doesn't work on outside-sliders though (you could reach in and lift the bar). Again I'm wondering who t.f. came up with these outdoor-sliders...Anyway, a great improvement for your home security, so go ahead and buy it.