RB493G is end of life (EOL). Mikrotik recommends RB435G for functional replacement.
The RB493G has nine Gigabit ethernet ports, three miniPCI slots and a switch chip so the ethernet ports of your choice can be grouped together to make it act as a switch.
The RB493G also has a USB 2.0 port and a microSD card slot for adding more storage or a 3G USB modem for backup connectivity.
The heart of this device is a high performance Atheros AR7161 CPU and it features 256MB of built in RAM. RB493G includes RouterOS – the operating system, which will turn this powerful system into a highly sophisticated router, firewall or bandwidth manager.
• Atheros AR7161 680MHz network processor (Tested at 800MHz)
• 256MB DDR SDRAM onboard memory
• 64MB onboard NAND memory chip
• Nine 10/100/1000 Mbit/s Fast Ethernet ports with Auto-MDI/X
• Three miniPCI slots
• Dimensions: 4.13 x 6.3in (10.5 x 16cm)
• Power consumption ~3W without extension cards, maximum – 16 W
• Operating System MikroTik RouterOS, Level5 license