This was fairly easy to install, after reading the included manual.  I love that you can have multiple users set up.  Our door is under a covered porch, so weather is not as much of an issue.  I'm not sure if it would be on a door that was more exposed.  I'm glad it came with 2 keys in case I forget the code or the batteries die.  This is really useful for when people come take care of our house when we're away and we can set them up with a code and then delete them after.  Very glad we have it!