This Nozzle kit is improved Compatible with Ultimaker 2 that the nozzle and heat block are two seperate pieces, can change the nozzle size easily. Filament size use: 3.0mm; Nozzles: 1pcs 0.25mm + 1pc 0.4mm + 1pc 0.6mm +1pc 0.8mm ; Package: 1pcs olsson block; 4pcs nozzles; 1pcs screw.