A quick and easy way to reduce the risk of blockages and clogging, these Outlet Balloon Guard Filters are simple to install without tools. Simply pushed into place these non-corrosive, polypropylene, flexible guards help to prevent blockages from leaves, roof moss, twigs and other debris from clogging your gutter. Universal to fit most downpipe openings, 65mm square or 68mm round, these outlet balloon guard Filters are relatively unobtrusive from ground level.