I bought one, thinking it was enough at the time, but then felt the lid of the toy box might be too heavy so I bought a second many months later. First one installed and operated just fine, but the second one slowed the the speed of the lid even more. But to be clear, one is all I needed. The lid is relatively heavy, perhaps 15lbs or more. I'm almost finished with the box.Regarding the installation instructions: the manufacturer did send me an email to english instructions which I didn't end up using since I didn't want to spend the time looking through my emails. But this is so easy to install the instructions in chinese would not have helped anyways. Make sure you have a metric ruler which I didn't have. Measure, punch, predrill and install. Super easy and fast. If someone had problems with this installation in the purpose I used them for, consider everyone's skill sets are different.I would buy them again. We'll see how they hold up to use over the next few years.
Rating: [5 of 5 Stars!]