The Realtek RTL8187B Wireless 802.11b/g 54Mbps USB 2.0 Network Adapter is a USB Wi-Fi adapter used for wireless network connectivity. It supports 802.11b/g Wi-Fi standards, which allow for wireless data transmission speeds up to 54Mbps. This adapter is commonly used for adding wireless network functionality to computers, particularly those without built-in Wi-Fi or with older Wi-Fi standards. It is typically found in budget wireless USB adapters or older devices.

The Windows driver for this device enables your computer's operating system to communicate with the wireless adapter and allow it to connect to wireless networks.