Portable baby seats in the nature of children's car seats; safety seats for children, for vehicles; safety belts and harnesses for safety seats for children, for vehicles; head rests for vehicle seats; safety mechanism for car seats, namely, energy shock absorbers; alerting systems for car seats, namely, alerts for failure in seat installation or child positioning or distress on seat; children's car seats equipped with sensors; safety belts and harnesses systems comprised of seat safety harne...