Westbrass 1-1/2 inch NPSM coarse thread Integrated overflow bath drain with tip-toe mushroom drain closure. European style round full-cover mushroom cap. Push down the cap to close and restrict draining water, and push again to open the drain-duty metal construction with an adjustable plastic tip-toe cartridge. Do not use plumber's putty for installation, use silicone seal. Note: Be sure to measure to ensure the correct size (Coarse or Fine). Available in a variety of stylish finishes, this item is sure to complement your existing fixtures. Westbrass Fine Decorative Plumbing since 1935.