The Britax One4Life All-in-One Convertible Car Seat and Britax Poplar S Convertible Car Seat Bundle offers two convertible car seats to accommodate your child from birth through the transition to a booster seat. The One4Life car seat features four configurations, converting from a rear-facing infant seat supporting 5-40 pounds to a forward-facing harness seat supporting 20-120 pounds. Its ClickTight installation system, steel frame, SafeCell technology, and V-shaped tether provide safety assurances. A 15-position headrest and no-rethread harness enable quick fit adjustments as your infant becomes a toddler. For comfort, the One4Life has a removable newborn insert and pillow, 9 recline positions, cooling mesh fabric, and machine-washable seat cover. Complementing the One4Life, the slim 17-inch Poplar S fits infants rear-facing up to 50 pounds and transitions to forward-facing mode. Its ClickTight installation and 14-position headrest/harness ensure proper fit, while the steel frame, SafeCell and patented V-shaped tether provide protection. The Poplar S features premium padding for comfort and a machine-washable cover for easy cleaning between rides. With trusted Britax safety and longevity from infancy through the booster seat years, this convertible seat bundle offers a comprehensive solution to keep your growing child safe and comfortable in the car.