*Returns not accepted on any opened, used, or defective product. Contact manufacturer directly for further defective products/parts. From Nuna, this car seat features: From cute preschooler to independent pre-teen. It's the longest and shortest time, and AACE grows right along with your child. Recommended use for high back booster: 40 to 110 lbs | 43 to 60 in, suggested usage 4 years + Recommended use for no back booster: 50 to 120 lbs | 43 to 60 in, suggested usage 5 years + 3D growth system: Grow up - one-hand, 9 position height adjustable headrest Grow out - shoulder system works simultaneously with the headrest, expanding out while growing up Grow on - seat sports 3 depths giving growing legs plenty of support and space 2-in-1 design - Converts from a high back to a no-back booster secure Comfy, built-in arm rests Energy-absorbing foam and SIP pods take side impact security to the next level Belt positioner aids in correct shoulder belt routing and minimizes user error Colored belt path indicators help decrease the risk of user error Lower anchor connectors allow for 8 position recline in high back mode & easily secure car seat to vehicle seat during use or transport From fabric to foam and beyond, each element is smartly sourced to be flame resistant with no added fire retardant chemicals Customizable recline with one-hand, 9 position headrest Ventilation panels within the shell and breathable (and washable!) knit fabric create a comfy climate for even the longest of trips Little arms can take a break thanks to cozy, built-in armrests Sleek and chic micro-knit fabric is easy to remove and machine washable Included AACE starter kit - with dishwasher safe cup holder, belt-positioning clip & a set of LATCH guides (included with purchase) GREENGUARD® Gold Certified to support healthier air quality and low chemical emissions Booster seat dimensions (highest position - HBB) L 15 in W 22.5 in H 33 in Booster seat dimensions (lowest position - HBB) L 14.6 in W 21.5 in H 26 in Weight: 15.6 lbs Imported.