2011 14″ Lenovo Thinkpad T420 (NVS4200M) [2nd,2C,M] + RX 460 @ 4Gbps-EC2 (EXP GDC 8.x) + Win10 // DIY HDMI input port: internal & external all in one LCD with button switch
Lenovo ThinkPad Port Replicator Series 3 with USB 3.0 - Port replicator - for ThinkPad L420; L430; L520; L530; T400s; T410; T410i; T410s; T410si; T420; T420i; T420s - Walmart.com
Lenovo ThinkPad 433810U Mini Dock Plus Series 3 X220 T420s T410s L520 + 90W AC - The620Guy.com
Lenovo ThinkPad Mini Dock Plus Series 3 Dock Station for T420 T420i T420s T420si | eBay