Stack Interface Module for 500 Series Switches. Model ES500MSI. P/N 683760-004.

Features:
1 port to allow connection between 2 Intel 500 Series Switches (Provided both switches are equipped with a Stack Interface Module)
400 Mbps
Full duplex
2 LED indicators to display port, link & data traffic activity
Intel Part Number: 683760-004

Intel MM#: 816077