Cisco 3800 Series Integrated Services Routers
The Cisco 3800 Series comes in rack mount form factor with a metal chassis and integrated power supply that offers a number of new enhancements ideal for secure higher performance data applications. It provides 4 VIC/VWIC/WIC/HWIC interface card slots that support WAN Interface Cards, Voice Interface Cards, Multi-flex Trunk Voice/WAN Interface Cards and High-Speed WAN Interface Cards (such as the HWIC-4ESW and the HWIC-D-9ESW). The cards are shared across platforms, i.e. within the Cisco 1700 and 1800 Series Modular Access Routers, the Cisco 2600XM Series and the Cisco 3700 Series (with the exception of the HWICs that are only supported on the new integrated services routers).
https://www.cisco.com/c/en/us/products/collateral/routers/1800-series-integrated-services-routers-isr/qa_c67-631674.html