This is a 4-inch to 4.5-inch flexing bellows coupler. This was designed for supercharged vehicles with 108mm throttle bodies. the high-grade 3.5mm thick silicone will stretch to 108mm on both sides if needed. the thickness of the silicone helps prevent the collapsing of the bellows. Not suited to post-bosted applications ie after pressure is added.
This includes 1X 4-inch to 4.5-inch coupler only. NO CLAMPS ARE PROVIDED IN THIS ITEM!
