NOTE: Please make sure to measure your current piston ring size. Some STI Models have slight different variations in o-ring size. Front seal kit to suit STI and Evo 4-Piston Brembo calipers. This kit will suit one front caliper only. 2 kits required for a pair of calipers. Kit includes: 4 Pressure Seals (4x46mm, 4x52mm) 4 Dust Boots (4x50mm, 4x56mm) Vehicle Fitment: 2001-2017 Subaru STI (4-Piston Brembo) Mitsubishi Evo 4-9 (4-Piston Brembo) Mitsubishi Evo X (4-Piston Brembo)