Designed with infants in mind, the UPPAbaby Infant Snug Seat provides extra comfort and stability for your baby's neck and back when strolling. Suitable from -3 months requires head and wedge and head support, at 4+ months (or when child can sit up unassisted) wedge and head support removed and used as liner. Updated design features improved head and wedge support while fully covering the toddler seat back. Must be used with Toddler Seat in the most reclined position with insert. Compatible with VISTA, VISTA v2, CRUZ, and CRUZ v2. Product Features: Creates a from birth solution for VISTA, VISTA V2, CRUZ, and CRUZ V2 toddler seats Suitable from birth to 3 months with use of head and wedge, 4+ months wedge and head support removed and used as liner Softly Cradles child while supporting their neck and back, improved head support and wedge insert provide extra stability Breathable Material keeps baby cool and comfortable Removable head and wedge support offers extended use as a comfort liner to grow with child