These Handy Magnetic Data Card Holders By U Brands® Make Building And Maintaining Your Planning Board A Breeze. To Use, Simply Insert Desired Cardstock Label Into The Side Slot Of The Magnetic Label Holder. Perfect To Visually Communicate Updates And Quickly Arrange Data As Needed, Or Simply Use As Removeable Labels For Filing Cabinets. Features A Strong Magnetic Hold That Is Perfect To Use On Any Steel Surface.