Booster Seat Weight

booster seat
An extra seat or cushion placed on an existing seat for a small child to sit on
An infant safety seat, also known as a child safety seat, a child restraint system, a restraint car seat, or ambiguously just as a car seat, is a restraint which is secured to the seat of an automobile equipped with safety harnesses to hold an infant or small stature people in the event of a crash.
(Booster Seats) Booster seats are not permitted in any Spaceships vehicle.
(Booster Seats) Are intended to be used as a transition to lap and shoulder belts by older children who have outgrown convertible seats (over 40 pounds). They are available in high backs, for use in vehicles with low seat backs or no head restraints, and no-back; booster bases only.

weight
the vertical force exerted by a mass as a result of gravity
A body's relative mass or the quantity of matter contained by it, giving rise to a downward force; the heaviness of a person or thing
The quality of being heavy
The force exerted on the mass of a body by a gravitational field
burden: weight down with a load
slant: present with a bias; "He biased his presentation so as to please the share holders"