Extended use from birth to booster. The Evenflo® Symphony All-In-One Car Seat accommodates children ranging from 5-110 lbs. with the most innovation and value on the market. Symphony provides exclusive safety features like SureLATCH® that automatically tightens to secure the car seat in the proper position. The Infinite Slide, Harness easily slides for an accurate fit every time. No reworking the harness as child grows, so parents can be sure children are properly secured every time.