Hi, which base will this need as a carseat?

Hi there, yes you will need the Nuna Base NEXT. The NEXT system offers ultimate flexibility with four solutions for the first four years, conveniently using one base for all compatible products. Here is a link to it here: https://www.babyonthemove.co.nz/products/car-seats/infant-capsules-bases/infant-capsule-bases/nuna-base-next/. Hope that helps.