You have to do one nail at a time, there's a timer for 60 seconds that turns off automatically. I'd recommend 2 x 60 seconds for each nail, don't hold the light too close or it'll sting (uv lamps can get hot) so keep it at least 3cm away from the nail. Cures fast, I'm using their nail gel polish as well and in a pinch you can use this as a nail glue for semi-clear press ons if you use a glob of their clear gel top coat underneath. (Pro tip; cure a clear layer on your nail first and sand it down before applying the press-on) but this may only last a couple days since it's gel. Overall, love this little lamp, using it to try out UV before I get a bigger lamp. Cute for beginners!