FODSLR Complete Square Filter Kit Compatible with Cokin P Series -Inclues:full Nd2 Nd4 Nd 8 Filter,graduated Nd2,nd4,nd8 Filtersgraduated Blue/orange/red/green/yellow & Purple Filer + 49/52/55/58/62/67/72/77/82mm Ring Adater + 2 PCS Filter Holder +2 PCS Lens Hood Gradual filter is a MUST for digital users, because the digital sensor unlike film has very low exposure tolerance. Detail will be lost on both low and high light area. To correct this, you need gradual filter to balance it! The Cokin creative system consists of 3 main components: An Adapter Ring + A Filter Holder + 1 or more filters