There's a button on the side to turn it on, and you'll find a typical four LED battery level indicator on the top. (digitaltrends.com)
The 5 - point harness is easily adjustable, and bubble level indicators on either side of the base ensure that the seat angle is accurate. (wetheparents.org)
Bubble level indicators on each side of the seat will help to make sure of that. (babyseats.reviews)