The Cisco 4000 series routers are the leading midrange/regional routers in the industry.  Supporting a vaiety of interfaces, the 4000 series can grow as needed and its versatility makes it ideal for integrating legacy equipment and protocols into a robust  IP network.

Models:

4500-M: 3 modular slots, 100MHz RISC processor and up to 32MB memory

4700-M: 3 modular slots, 133MHz RISC processor and up to 64MB memory