The FreePBX Sangoma 1200 appliance as outlined below and FreePBX Distro. In this configuration the Appliance is recommended for up to 1200 extensions and 300 concurrent calls. Specifications of the Appliance are as followed; 1U Server 4 PCI Express Slot 6 Onboard GIG Network Ports Dual 500 GB SSD Raid Drives i7 Quad Core Processor 16 GB of Memory Dual Power Supply Rackmount Rails 1 Year Hardware Warranty 22in D X 17in W X 1.75in H Box size is 28in L X 20in W X 8in H and weighs 30 lbs