Our comfortmodel 4-S is often used by parents who take their baby for long rides into their biketrailer or childrentransportbike or for daily use! Perfect for parent who leave the seat outside in their transportbike! Our COMFORT 4-S model consist of an EXTRA FOAM CUSHION under the cover AND at the sides as well! That is the only difference between our basicmodel.If it later turns out that you would like to upgrade your babyshell with inlays of a carrystrap it is possible. This cover is droprepellent, babysoft, fungicidal and dirt-resistant.  This cover is also superabsorbing moist from your baby.