I have several 3.5" ID silicone couplers. They are a little longer than 3" each. They are ThermaFlex brand, very strong, reinforced, multi ply. I have 6 of the 3" long pieces, and 1 6" long piece. I also have a 3.5" hump hose, and a reducer, I have to measure it. All items are in excellent to new condition. Whatever items you want, make me an offer and we'll work it out. Thank you.