Pick how you're putting it in. Each way is from the maker's manual.
Base with LATCH
Where it can go: Rear-facing only child restraint: never in front of an active airbag; the back seat is safest. Only on forward-facing vehicle seats. Rear center with lower anchors only if the vehicle maker approves it and the anchors are no more than 22 in. apart; otherwise use the seat belt or an outboard seat. No top tether is used.
1Park on level ground. For the recommended load leg install, press the release button under the base, pull the load leg out and place the base with the leg toward the front of the seat cushion (removing the floor mat is recommended).
2Lift the level adjust handle to extend the foot until the bubble on both level indicators is fully between the lines.
3Push the orange buttons, pull out the lower anchor connectors and clip them to the vehicle lower anchors, facing upright.
4Press firmly into the base (a rocking motion may help) until the webbing tightens and the tightness indicator turns green and stays green.
5Make sure the Anti-Rebound+ panel touches the vehicle seat back fully.
6Rotate the load leg extension until it shows fully green, then pull the two ends apart so the foot sits firmly on the floor with no red showing; recheck the bubble.
Check it before you drive
Base moves no more than 1 in. side-to-side or front-to-back at the belt path; anchor webbing is secure and untwisted.
Tightness indicator is green every time you use it.
Level bubble is fully within the lines, no partial bubble.
Load leg is secured, touches the floor and its angle indicator is green.
Store the load leg under the base when not in use.
Retold from UPPAbaby manual (PDF). Your vehicle's manual also says which seats have LATCH anchors. When in doubt, a certified child passenger safety technician can check your install.
The carrier on and off the base
Clicking it onto the base
1Lower the carrier onto the installed base until you hear a click.
2Pull up on the carry handle to check the carrier is locked on.
3Before driving, lock the carry handle in either the 5th (rebound) position or the 4th (carry) position.
The maker warns: In the vehicle the carry handle must be in the 5th (rebound) or 4th (carry) position.
The Aria V2 base: LATCH + seat belt base (auto-retracting LATCH, built-in lock-off), load leg, Anti-Rebound+ Panel.
What UPPAbaby says about its bases and carriers, for a second car or an older base.
A Mesa V3 carrier clicks into the original Mesa base and the Mesa V2 base, so an older spare base still works with the newer seat. UPPAbaby help article
The newborn insert
What UPPAbaby says about the insert
1The insert has two parts: a preemie cushion and a back positioning insert. Use it from 4 lbs, up to about 4 months.
2Find the fastener tabs inside the headrest, at its upper left and right.
3Tuck the back positioning insert's tabs under the headrest fabric and press to secure.
4Fit the preemie cushion around the buckle. It is only used together with the back positioning insert.
5Take the preemie cushion out at about 9 lbs; the back positioning insert can stay on its own until about 4 months.
6Keep using the insert until all fit checks are met: straps at or slightly below shoulders, chest clip at armpit level, no slouching, buckle snug with no gap, and harness passes the pinch test.
The maker warns: Harness pads are optional but must be removed when securing a preemie. Always check the recline indicator on the base is in the range marked for infant insert use.
Rear-facing only child restraint: never in front of an active airbag; the back seat is safest. Only on forward-facing vehicle seats. Rear center with lower anchors only if the vehicle maker approves it and the anchors are no more than 22 in. apart; otherwise use the seat belt or an outboard seat. No top tether is used.
How do I know the UPPAbaby Aria V2 is installed right?+
Base moves no more than 1 in. side-to-side or front-to-back at the belt path; anchor webbing is secure and untwisted. Tightness indicator is green every time you use it. Level bubble is fully within the lines, no partial bubble. Load leg is secured, touches the floor and its angle indicator is green. Store the load leg under the base when not in use.
When do I use or remove the UPPAbaby Aria V2 infant insert?+
The insert has two parts: a preemie cushion and a back positioning insert. Use it from 4 lbs, up to about 4 months. Find the fastener tabs inside the headrest, at its upper left and right.
