1. I bought it because the screen is large and easy to see. 2. I have a thermometer, hygrometer, and clock with date and day of the week functions that I bought about a year ago, and it's working properly as a wall clock. 3. There is no instruction manual, but I have the original box, so I will wrap it in bubble wrap for shipping. 4. Batteries are also included. Please understand that this is a used item, and only those who understand this are welcome to purchase.