SNS = Safe and Sound - they'd be the most popular brand
Convertible booster- is one that can have a child from 9-26kgs. They have an inbuilt harness that takes up to 18kgs, that you remove once they are past the weight limit. I wouldn't suggest a 9kg child use these though... they would be a bit small adn the seat is so big.


Here is the seat I have:
Product Range - Infa-Secure

and here is a link to the ratings from 2009
http://www.racv.com.au/wps/wcm/conne...f18f53baa8cac0