Brass & Stainless Steel All Metal & Rustproof: The bathroom sink pop-up drain stopper is made of brass and 304 stainless steel without any plastic parts. High-quality workmanship ensures that the pop-up sink drain is resistant to scratches, corrosion and discoloration, making it rust-proof and durable Solid Metal Construction: Made of explosion-proof, crack-resistant and thickened brass and premium type 304 stainless steel Multiple Leak-proof Design: The included high-quality thick silicone gaskets fit the drain better and are anti-oxidation. With 3-piece sealing ring design, the sink drain prevents water leakage more effectively Overflow-free Drain Unit: This bathroom drain fits most undermount or recessed sinks without overflow. Drain opening diameter: 4.1-4.8 cm. The maximum thickness of the sink is 5 cm Dimensions: Total length of the black sink drain: 22.2 cm. Pop-up stop diameter: 6.6 cm. Tail Piece Nut Diameter: 1.26"