The DGS-3120 xStack Switches are enhanced L2 stackable switches designed to connect end-users in a secure SMB or enterprise network. These switches support physical stacking, multicast and enhanced security, making them an ideal Gigabit access layer solution for any network. Replacing DGS-3100-48P model.Important! Please note:· DGS-3120-series are not stackable with the DGS-3100-series. · DGS-3120-series do not come with stacking cables. They need to be purchased separately (DEM-CB50/DEM-CB100).· DGS-3120-series have two versions: Standard Image (SI) and Enhanced Image (EI). Dlink are only stocking Standard Image models. Enhanced Image models offer advanced features and only available for projects. You cannot buy a SI model and upgrade it to EI.