2nd Seat Kit 3.0
$
175.00
Free shipping & returns for Babylist orders $45+
color
Black
1
Overview
Description
The 2nd Seat Kit allows you to expand your Mockingbird Single-to-Double Stroller (sold separately) into a double stroller.
The kit comes with a 2nd stroller seat, as well as a set of adapters to make room for two riders.
If you’re planning to stroll with one of your kids using the bassinet or car seat adapter, you’ll still need the adapters to convert to double mode, and then you can start using the 2nd stroller seat when your child develops head and neck control (typically around six months).
The seat in Mockingbird’s 2nd Seat Kit is identical to the seat included with the Single-to-Double Stroller. This means you can stroll in double mode with two kids up to 45 lbs, and you can choose to have your younger child closer to you.
It also means that the 2nd seat has all the features of the Stroller seat, including the FullShade system, which pairs the XL UPF 50+ canopy with the built-in LegShade for head-to-toe coverage sun coverage.
Other parent-favorite features include the magnetic buckle, height-adjustable canopy, reversible seasonal seat-liner, reflective piping for safer nighttime strolls and more in-seat storage.
Note: To stroll with twin infants, you’ll need the 2nd Seat Kit plus two Car Seat Adapters or two Infant Seat Inserts, as the Single-to-Double Stroller is not compatible with two Bassinets.
What we about it
Expands your Single-to-Double Stroller to double mode in under a minute, no tools required.
Details
- What’s included: Seat, Upper Adapters (to raise your 1st Seat and make room for the 2nd) and Lower Adapters (to attach the 2nd Seat)
- Max. child weight: 45 lbs in each seat
- Compatible with the Mockingbird Single-to-Double Stroller (all models)
- Cannot be used with the Mockingbird Single Stroller
- Babylist exclusive: Heather Grey
Frequently added together
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Q&A
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Customer reviews
1,107 Ratings
1-10 of 1,107 Reviews
Excellent Product
This product has been a life saver for baby number two! We love being able to have both of our littles in one stroller without all of the hassle! Excellent product!
Oct 4, 2026
Very difficult to control
This stroller as a single is great, I love it. But once you add the second seat it becomes soooo difficult to control. The weight distribution no matter if you have your older child on top or bottom is so hard to manage, and I would consider myself a very strong person. Also, if you use the bassinet up top with the toddler seat down below facing forward, the toddler has to be sitting straight up as far as it goes (and my toddler likes to relax on walks, so this doesn’t go over well with her).…
Sep 21, 2026
Worth the upgrade 🙌
So glad I upgraded to the newer seat! The leg shade has been amazing for summer! The canopy goes down lower than my older version which is great! The two mesh pockets on the side is perfect for toys or snacks for my toddler to find. The phone sleeve in the back is super convenient when I don’t have pockets, there’s also another pocket lower down that can fit diapers and wipes which is super convenient for a quick trip! I use it to store a few extra snacks, onesie, diaper, wipes! So easy to wipe…
Sep 16, 2026
I was sent two of the same pieces so i couldnt move up the oroginal seat and the bottom adapters wouldnt connect to my new seat.
Sep 5, 2026
Seat Kit 3.0
I LOOOVEEEE the new upgrade. The extended shade my baby gets and the leg shade cover too! I am waiting to upgrade my second 2.0 seat to the 3.0 seat and can’t wait to buy the second one! I also love the new black finish i stead of the silver.
Sep 3, 2026
Easy & Convenient
I love that we don’t need to buy a whole new stroller, and that there are accessories and kits that include EVERYTHING you need. No confusing manuals, no confusing parts. Great buy. Highly recommend.
Sep 3, 2026
So easy!!
I was worried going from the single to the double set up would be a little complicated but it is so simple and also easy to go back to the single set up if needed. Highly recommend!!
Sep 2, 2026
2nd seat
I love my mockingbird!!! Great for my two children
Aug 31, 2026
Not as nice as the old one
I bought a second seat for my second baby and the buckle system absolutely sucks to use, especially with a squirming baby. The magnetic flap on the sunshade doesn’t reach the opposite magnet so it doesn’t stay open. I do like the extra pocket and how the seat is an insert you can easily take out to wash and the sunshade is also easier to disconnect to wash. However, I may hesitate to buy another seat if the buckle situation doesn’t change. First seat I bought in 2023- great! Second seat I bought in 2025- meh/frustrating.
Aug 24, 2026
Love!
This stroller and the 2nd seat attachment have been a huge lifesaver with my twins. It is so easy to switch between the seats or the car seat attachment.
Aug 21, 2026
