Built for contractors or DIYers looking to up their game, the PRO KIT comes supercharged and fully-loaded with everything you need to install buried downspouts with maximum performance. Available in 3 in. corrugated or FDM's New 3½ in. corrugated. If you need a wye fitting you can purchase one here: 3 in. OR 3½ in. Corrugated Wye Fitting