an infant car seat with an adjustable base platform provides a variable angle of tilt for the seat . the base platform has a visual indicator showing the degree of tilt that has been selected . this visual indicator can include a clear plastic window in the base platform , through which a number or other symbol indicating the degree of tilt can be seen . the user can adjust the degree of tilt by depressing a button to disengage a locking mechanism , allowing the user to vary the degree of tilt until the desired degree of tilt is indicated on the visual indicator .