Works with A or B elbow. 2 x 3 in or 3 x 4 in. Snap-fit technology for easy installation. Unobstructed interior flow to prevent clogging. Beaded seal to avoid leakage. Low profile 2-1/8 in high drainage diverter. Directs water away from foundation. Optional extender increases overall length capacity an additional 30 in. Snap-fit design secures the extender in place for long term positioning. Telescoping feature allows owner to adjust the length that suits their application. Extends to over 50 in length.