From Nuna, this system features:

This all-in-one PIPA Urbn Flex system gets that parenting demands flexibility, and your gear needs to keep pace with the pivots. So it flexes with your day, transforming from a car seat to a stroller so you can go from parked to pushing and back again in seconds.

Frame folds with the car seat ring adapter attached and stands on its own when folded
Travel system ready-compatible with the SWIV(TM) & TRIV(TM) series bassinet, the Flex system stroller seat, and any PIPA series car seat using the included folding ring adapter
Car seat installs with ease using pipaFIX(TM) or vehicle seat belt-no base or dirty wheels
2-second steel-reinforced pipaFIX(TM) rigid latch installation
Car seat releases from vehicle with 1 hand for quick and easy in-and-outs Auto-reclining car seat foot aids in proper installation
FAA certified for aircraft use
Car seat is not compatible with PIPA series base or RELX(TM) base Quick-engaging 1-touch rear-wheel braking system on frame provides scuff-free security
Aeroflex(TM) foam on the car seat is cleverly lightweight, resilient, and minimizes force
Car seat features Side Impact Protection (SIP)
5-point harness helps keep travels secure
All-wheel suspension and durable, never-flat tires on frame
Full-coverage UPF 50+ canopy, extendable and a flip-out eyeshade and XL peek-a-boo window
Head support in car seat includes a 2-layer soft surround to accommodate smaller babies
Infant head support and body inserts feature environmentally friendly Merino wool and TENCEL(TM) branded lyocell fiber blend that is soft and naturally moisture-wicking (TENCEL(TM) is a trademark of Lenzing AG)
Large basket holds up to 22 lbs
Tracking device pocket in the basket
Height-adjustable 3-position pivoting handle
Carbon fiber reinforced aluminum frame
Carbon fiber's unique weave pattern on the frame
Iconic Sky drape(TM) on car seat pulls down smoothly and attaches quietly with magnets
Luxe leatherette accented push bar
Includes a carry bag
Carbon fiber reinforced aluminum carry handle offers lightweight strength and durability
Carry handle is accented with luxe leatherette
Integrated magnetic buckle holders on the car seat
Machine washable seat fabrics and inserts
From fabric to foam and beyond, each element of the car seat is smartly sourced to be both flame resistant and contain no added fire-retardant chemicals
Set of included car seat latch guides make the lower anchor bars in your vehicle more visible and accessible for easier installs
Flex system frame:

Up to 50 lbs
Frame Weight: 8.5 lbs.
Frame + Adapter Weight: 11.3 lbs.
Approx. Stroller dimensions (open):37" L x 21.5" W x 43.5" H
Approx. Stroller dimensions (folded):23" L x 21.5" W x 29.3" H
PIPA urbn:

4 to 30 lbs and 16 to 29 in
Weight: 7 lbs without canopy and inserts (canopy and insert approx. 2 lbs) Car seat dimensions: L 25 x W 17.5 x H 22 in