84mm connection for the MAF (same as OEM) 71mm connection for the Turbo (same as OEM) Socket for BOV recirculation (25mm) is located on the hose underside. This is for those who do not use the original by-pass valve in the turbocharger. Plug is included if this is not used. The hose is reinforced with steel wire so it won’t collapse during high vacuum.This hose kit is available in three different colors Blue / Black / Red. There are no performance difference between the different colors, choose which color you think will be best for your car.