Detail overview
   Hp - Procurve Vl 20p Gig-t+ 4p Sfp Module Switch Expansion Module - 20 Ports (j9033a). 
 Key Features : 
  Device Type : Expansion Module - 20 Ports 
   Form Factor : Plug-in Module 
   Features : Auto-uplink (auto Mdi/mdi-x), Half Duplex Mode, Full Duplex Mode 
   Compliant Standards : Ieee 802.3, Ieee 802.3u, Ieee 802.3ab 
 Networking : 
   Connectivity Technology : Wired 
   Cabling Type : Ethernet 10base-t, Ethernet 100base-tx, Ethernet 1000base-t 
   Data Link Protocol : Ethernet, Fast Ethernet, Gigabit Ethernet 
   Auxiliary Ports : 4 X Sfp (mini-gbic) 
   Data Transfer Rate : 1 Gbps 
 Expansion / Connectivity : 
   Expansion Slots Total (free) : 4 ( 4 ) X Sfp (mini-gbic) 
   Interfaces : 20 X Network - Ethernet 10base-t/100base-tx/1000base-t - Rj-45 
   Compatible Slots : 1 X Expansion Slot