Tandem pushchair twin pram recommended minimum age new born pushchair weight 125 kg carrycots pushchair seat second seat harness system 5 point safety harness slider adjustable handlebar height 72 112 cm series hauck freerider special feature upholstered seat wheel settings swivelling lockable wheel type solid rubber tyres wheel diameter rear 29 cm wheel diameter front 23 cm number of wheels 3 safety bar with bumper bar footrest adjustable