Refurbished: HP Elitebook 720 G1 720 G2 725 G2 725 G3 UltraSlim Docking Station - Newegg.com
HP EliteBook 840 G3 Core I5-6300U 2.4GHz SSD 180Gb RAM 8Gb with HP dock station [Y1Y02US#ABA] - $599.00 : Professional Multi Monitor Workstations, Graphics Card Experts
HP UltraSlim Docking Station 2013 - docking station - VGA, 2 x DP - D9Y32UT | howardcomputers.com
Amazon.com: iBuyMax USB-C Docking Station Cable for HP Elitebook 840 G3, X260 1030 G2, Elite X2 1012 G1, Single Custom end (AC + USB Type-C to USB Type-C), Black : Electronics