The UPPAbaby Lower Adapters transform your Vista stroller into a versatile double configuration by allowing a bassinet, RumbleSeat V2+/V3, Aria, Mesa?V2, or Mesa?Max infant car seat to attach as a second (lower) seat. Each adapter features large hubs with intuitive color-coded indicators for tool-free installation and securely lock into place. They remain on the stroller when folded and include a closure lock for added safety. Specifically designed for Vista models from 2015 onward and compatible seat options, these adapters expand your strollers functionality with ease.