The Liderpapel 408 20mm metal hinged binding ring, no. 1, box of 20, allows you to group perforated sheets and samples with complete mobility. The package contains 20 nickel-plated steel rings with a 20mm internal diameter and a hinged pressure closure for easy opening and a firm seal. The metal mechanism allows you to flip paper 360 degrees without tearing the edges. It is the ideal solution for creating sample fans, handmade calendars, photo albums, and document binding.