How to Easily Add RAM to Your Windows or Mac Computer - wikiHow
So if you have a single slot, you must choose a bigger RAM module. If you have an additional, you can buy and add another.
and 2 slots for fast Ethernet modules - ANS Vietnam (Anh Nghi Son ...
ANS là Đại lý MOXA Vietnam,Ethernet module slots and 2 power module slots PT-G7828 MOXA Vietnam, MOXA Vietnam, ...
RKS-G4028-PoE-4GS-LV-T: Modular managed Ethernet switch with 4 100/1000BaseSFP ports, 3 slots for Ethernet modules, PoE Ethernet module supported, 1 isolated power supply (24/48 VDC), -40 to 75°C operating temperature - BKAII - Thiết bị truyền thông tốt nhất với giá cạnh tranh nhất
RKS-G4028-PoE-4GS-LV-T: Modular managed Ethernet switch with 4 100/1000BaseSFP ports, 3 slots for Ethernet modules, PoE Ethernet module supported, 1 isolated power supply (24/48 VDC), -40 to 75°C operating temperature