This swing seat was purchased to substitute a seat included in a large swing set from Costco.  The infant/toddler seat that's included with the set doesn't hold our 19 month son securely enough.

This seat is great b/c it supports his head and prevents him from sliding forward in the seat.  Also, this swing is sturdy and won't wobble as much while the seat is swinging due to the 4 string attachment points vs. the typical 2 to regular infant seats.