The Baby Jogger Summit standard seat is approved for use from birth, it can be reclined to virtually flat.
To recline the seat simply squeeze the clamp to release the strap.
Lower the seat to the desired angle and release the clamp.
The seat back will now rest on the strap in this lower position - either at it's maximum recline or whatever angle you require.
Seat Ventilation
The rear of the seat has a mesh fabric allowing good ventilation and some visibility of the child. To avoid draughts and provide weather protection the mesh back can be covered.