This article covers wireless networking options for the OptiPlex 3020 / 9020 Micro.
When ordering an OptiPlex 3020 / 9020 Micro system, you have the option of including the Intel Dual Band 7260 802.11AC w/Bluetooth wireless networking kit (wireless card, mounting bracket, cables and antenna) in the system.
Factory Wireless Kit cannot be added to system after purchase.
If the wireless networking option was not selected at the time of purchase, then the factory kit cannot be installed after purchase because the mounting hardware is not available for sale after system purchase to install the wireless card.
If you desire to add wireless capability to an existing OptiPlex 3020/9020 Micro system, then a USB wireless adapter is the recommended upgrade option. Please see the Dell Accessories site and enter "USB wireless adapter" in the search box for available options.