3 wheeler pushchair sport buggy recommended minimum age 6 months backrest continuously adjustable brakes locking brake canopy removable harness system 5 point safety harness suspension slider adjustable handlebar height 78 111 cm folding mechanism one hand fold wheel settings removable wheel diameter rear 28 cm wheel diameter front 23 cm number of wheels 3 recommended maximum age 3 years safety bar removable footrest 2 way adjustable dimens