There are several alarm sounds to choose from beeping to music. Alarm volume can be adjusted, it can go very loud, which we needed. You can change the colors of the letters also. It was hard to get good picture due to it having a mirror so it is much clearer in person. You can also adjust brightness of the numbers. It comes with a USB charger. You can also charge you phone from the clock. It has a battery CR2020 which is very hard to get out unless you pry the little thing the battery goes in. I'm not sure what the battery is for because I couldn't get it to work with just the battery and not plugged up, maybe a dead battery? Anyway the clock does what I wanted:Loud alarm and Big numbers!