If you are looking for a small form factor machine with multiple ethernet ports for use as a firewall appliance this little device is fantastic.
It includes a quad core Celeron CPU and four ethernet ports, but you will need to add a mSATA drive and some memory.
I added a 256GB mSATA card and 8GB of memory. It runs great and can handle the throughput of my 1Gb internet connection.
I’ve been looking for something like this for a while and it’s a fantastic device for running Sophos XG firewall on using the home license version.
Check it out.