Child car seat series cybex silver carry weight 9 18 kg age 9 months 4 years group 1 with isofix side impact protection harness system impact cushion padded seat belt padded clasp exterior measurements 40 x 55 x 61 66 weight 67 kg adjustable backrest central belt adjustment height adjustable adjustable headrest 8 x seat reducer manufacturer specific features lsp system slip cover washable cover