2nd LED HD Hard Drive Caddy Adapter ultrabay slim for Lenovo ThinkPad T400 T400s | eBay
Ultrabay Slim SATA 2nd Hdd Hard Drive Caddy for Module Lenovo ThinkPad T400 T500 New 9.5mm - AliExpress
NEW USB 2.0 Cable to SATA 2nd HDD caddy DVD CD ROM Ultrabay Slim SATA with LED indicator - AliExpress
Jeyi Q8 Universal 2.5' 2nd 12.7mm Ssd Hdd Sata Hard Disk Drive Hdd Caddy Adapter For 12.7mm Height Cd Dvd Rom Optical Ultrabay - Hdd & Ssd Enclosure - AliExpress
Adding a aftermarket hard drive caddy in the optical bay (T61) - Thinkpads Forum