Hi, can you attach any other brands capsule with an adapter?

Hi Gemma, unfortunately, the Nuna TRVL Dubl stroller is only compatible with Nuna’s PIPA-series infant car seats—such as the PIPA, PIPA RX, PIPA AIRE, and PIPA URBN—and no adapters are required for these. Nuna strollers are designed with an exclusive fit for their own PIPA car seats. While some strollers (like UPPAbaby’s Vista or Cruz) offer adapters to use other brands (Maxi‑Cosi, Cybex, etc.), the TRVL series—including the Dubl—does not support any non‑Nuna brands. Hope that helps