Mishimoto MMHOSE-CIV-12SIIHBK Honda Civic Si Silicone Induction Hose, 2012&ndash;2015, Black Direct fit for 20122015 Honda Civic Si INNER DIAMETER: 2.75" - 3.1" OUTER DIAMETER: 3.15" - 3.5" Installs in under 30 mins and its with stock airbox Silicone and steel rings for added reinforcement and resistance to collapsing Mishimoto Lifetime Warranty