3com Router 4-Port ISDN S/T MIM networking card

Router 4-Port ISDN S/T MIM Maximize Performance with Optional Interface Modules
These Multi-function Interface Modules (MIMs) provide a variety of expansion options that let you enhance router performance to optimize network operation. Customize your network to your business needs.
Provides ISDN BRI S/T capabilities
Facilitates scalable and secure network operation
Maximizes interface density and slot efficiency
For use in 3Com Router 5232 and Router 5231, Router 5642 and Router 5640, Router 5682 and Router 5680