I installed this closer on a fire-rated, weather-stripped, metal door that did not have a closer. This door exited out from my house into the garage. I needed a closer with an option for a parallel arm mount. Several “top ten” website rated this one highly, and its price on Amazon was lower than expected.The “user manual” is just diagrams with specs, one page for each of the three installation options (regular arm, top jamb, and parallel arm). Fortunately, I found several videos on-line for closers similar to this one. Be advised that the “installation manual” for this product is just the templates.Since I had never installed a closer before, I would have appreciated some step-by-step instructions. But as I proceeded to install the closer, I realized it was lot easier than I thought. For me, the templates were great, and saved me a lot of time figuring out the spec sheets. All the necessary parts were included, along with many extra parts. Now that I have installed one of these, I am quite confident I could do it again without any instructions.The closer operates at one speed until it reaches the set backcheck angle, and then goes faster to make a secure close. I fiddled with the latching and speed regulation valves for about 20 minutes until I got the door to close securely every time, despite the weatherstripping. I expected I would have to increase the backcheck angle but that proved to be unnecessary. My compliments go to the factory for their initial settings. For now, I am leaving off the plastic cover in case I need to make some more adjustments after the closer settles in.I am very pleased with this closer, and I would buy it again.Update: The closer has been installed for a week, and showing no sign of needing recalibration. So I have put on the cover for a nice look. In the parallel mount position, the screws holding the cover are at the top. I decided to just use a few toothpick points instead of the provided screws in case I want to make adjustments later. Still working great.