38mm Heavy Duty Roller Blind Sidewinder / Control + Control Mechanism w/ Chain | eBay
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) :
Changing Roller Blind Chain - YouTube
DIY Automated Roller Blinds | Hackaday
Non-standard installation of roller blinds. How to install roller blinds DIY - YouTube