Product Info Catalog Plumbing Stove Pipe & Chimney Pipe 6 x 6-Inch Flexible Coupling Connects Concrete to Concrete 6 x 6-Inch Flexible Coupling Connects Concrete to Concrete Request a Quote UPC: 18578001176 SKU: 528901 Model Number: P1004-66 6" x 6" flexible coupling, concrete to concrete. Made of tough PVC and corrosion resistant, rustproof clamps.