I bought this timer for use outdoors as a timed outlet for our swimming pool's salt system computer. The instructions state that the device is weatherproof, but for added security I cut off the timer's plug, extended the wire several feet and enclosed it in electrical conduit. I then connected the wire directly to 120 VAC inside a weatherproof junction box mounted to the wall.As noted in at least one review, the plug-in area of the timer is recessed. For example, when mounted vertically on a wall, this lip extends below the base of the plugs and functions nicely as a rain drip to help weatherproof the connections. Personally, I appreciate this. It is a nice feature so long as you don't try to plug in a device with an over-sized plug. Of course, there's an immediate cure for the 'big plug problem': Replace it with a smaller one. Many gadgets these days have oddly shaped or right angled plugs. Such would need to be replaced to work with this timer, or you could elect use an external power strip.I found the instructions overall to be OK. I was able to set an initial on and off event successfully with my first try. The programming logic is pretty much standard for most digital devices and made sense to me as I went along. This timer has some complex capabilities. For example, it has an 'astronomical' function that keeps track of your local dawn and dusk. To facilitate this, the setup includes entering not only your state but also where in your state you happen to be. The timer automatically tracks daylight savings vs standard time, and has provisions for customizing the dates and times of these transitions if your location happens to be non-standard.One feature that I particularly like: this timer has a battery backup for all schedules, including the clock time. If you lose AC power, the timer's battery backup will hold all your clock and timer settings for three months. In fact, this was the primary reason I needed to buy an external timer for our pool salt system. It's internal timer had a battery backup for scheduled functions, but if there was a power outage, even momentary, the clock reset to 12 a.m. This would place the salt unit entirely out of sync with the pool pump. Fortunately, the salt system computer has a setting allowing use of an external timer instead og the internal one.This timer only handles 120V at up to 15 amps. If you want to control 220V devices, choose a different timer.Overall, a great value for the money, and just the timer we needed.