BIBISTORE Solar Heat Sensitive Automatic Greenhouse Window Opener Hothouse Vent Openers Auto Vent Kit Greenhouse Accessories-(Two Springs,Lifts 15.4 Lbs)

Work good for 2 years.

I followed the instructions and refrigerated the piston while figuring out how to mount the vent arm to the frame of the greenhouse. I ended up using hardware that came with my greenhouse, the actual process of installation will depend on your specific greenhouse. If you are handy, you will figure it out pretty easily. There are several holes in different sizes for mounting the arm to the sill. My existing hardware fit into the larger holes. I didn't use any of the hardware that came with the opener. I had to slightly widen the holes on the window end of the arm. If you want something that works right out of the box, you'll need to buy an opener made by the same manufacturer as your greenhouse.It was a warm spring day when I installed the opener and within a few minutes it fully opened the vent. Hopefully it lasts several years.

This opener fit perfectly on my Harbor Freight 6x8 greenhouse. It was relatively simple to install if you are somewhat handy. I didn't need the instructions as it was pretty simple to understand. You are able to twist the black piston right and left to screw it in and out to adjust when it will begin opening. If it opens too early in the day, you screw it to the left, if it opens too late, screw it right very simple. I have it screwed about halfway, and my greenhouse stayed at 85 degrees all day until it started to cool off and they closed. Day 1, they are working as expected, will have to see if they continue to perform!

While it works after 3 days in service, it is :1) Not made for the metal greenhouses (I bought a 6 x 6 x 8 metal framed unit on Amazon). It's made for wood framed windows.2) The instructions are terrible.I had to modify how I attached the unit to my metal framed windows which was a rather complicated process, especially as the original instructions were so bad you couldn't determine how the various parts were installed. Then you also had to get the needed parts.

Got two of these last year. Got one at first to see how it worked and then a second one. They worked as described through the season. I removed them at the end of the season as I wasn't sure how the winter cold would affect them, if at all. They were stored over the winter months in the basement. This spring I can only get one to work, the piston in one doesn't function. Last year they were both very dependable but this year not. I don't know what went wrong. I'm going to see if I can get a replacement piston.Initially gave this a three but downgraded it due to the failure of the second of the two I purchased last year.

Mine worked great for my Grandio greenhouse. However the top bracket that attaches to the vent (the part that lifts up) wasn't wide enough for the existing holes. So I could only get one screw in. This opener is a lot cheaper, compared to the 70$ ones on Grandio's website. The only reason why I am taking one star off is because the instructions were HORRIBLE! I was looking at pictures and watching YouTube videos.***NOTES*** If you buy this, make sure it's well lubricaded. If it's not, it won't work or last for long. I don't think they mentioned that in the instructions. The more more you push/screw the rod in, it'll lift at the coolest temperature. I have mine screwed in almost all the way and it begins to lift at 65°/70° F. Make sure you take the rod inside during winter time (can damage if it freezes).

My husband built a greenhouse. These windows are made to open when it gets too hot. Perfect!!

In spite of less-than-complete directions, this vent opener installed quickly and easily, with the only modification required being to widen one end of the slots to accommodate the standard Palram bolts. I did that easily with a drill and properly sized drill bit, and installed the device. The only piece lacking was the cotter pin to connect the cylinder to the vent tube. However a large paper clip is doing the job temporarily.I'd also like to add that I previously upgraded the rather flimsy Palram "hinge" with a piano hinge also from Amazon, and the window is solid even in our seasonal desert wind gusts. You will also notice cables over the entire structure, connected into strong anchors near the base.I am hopeful that this device will have a long life!