Amazon.com: Luanxu 4.5 mm Stainless Steel Bead Chain for Blinds & Shades with 5 Connectors, Fix or Replace for Broken Roller Blind Curtain Chain, Great Pulling Force & Rustproof (#10, 3 Meters) :
Amazon.com: White Plastic Chain Connector for Beaded Chain for Roller Shades and Vertical Blinds (pack of 10) (chain not included) : Industrial & Scientific