You're looking at a Dell Inspiron/Latitude D Series Advanced Port Replicator. Dell model number PR01X, part number P8129. The Dell D/Port Advanced Port Replicator integrates your Dell computer quickly and easily into a desktop environment. Works with the newer Dell laptops.
Compatible with the following laptops:
DELL INSPIRON: 500m, 510m, 520m, 600m, XPS M1710
DELL LATITUDE: D400, D410, D420, D500, D505, D510, D520, D600, D610, D620, D800, D810, D820
DELL PRECISION: M20, M60, M65, M70
I/O Connectors: Serial: One 9-pin connector; Parallel: One 25-pin unidirectional, bidirectional, or ECP connector; PS/2: Two 6-pin mini-DIN connectors; USB 2.0-compliant connectors: three standard USB, one powered USB; Audio: Audio line-out connector for headphones/speakers; Digital audio: S/PDIF; Network: one RJ-45 port (10/100/1000 GB); Ethernet Modem: one RJ-11 port; Video: Digital video interface (DVI), one 24-pin connector; S-video: (TV-out) one 7-pin mini-DIN connector.