Penkid window restrictor 5 pack allows you to safely baby proof your windows to protect your toddler from dangerously wide open windows the window restrictor kit comes with five penkid window locks and five sets of keys and screws to ensure you have everything you need to protect your little one the penkids are easy to install using two screws on either side and are suitable for use on wood pvc metal and aluminium window frames without leaving any damage the penkid has been designed with a