Startech 10/100Mbps PCI Fast Enet Network Card Add a 10/100Mbps Ethernet port to a desktop computer through a PCI slot Dual RJ45 Ethernet ports in an ExpressCard/34 adapter Microsoft NDIS5 Checksum Offload (IPv4, TCP, UDP) and Large Send Offload support Compliant with IEEE802.3 CSMA/CD, 802.3 10Base-T and 100Base-TX standards Cost effective and simple Ethernet networking for a desktop computer systems for selective Windows OS