Yeastar S2 Module PBX (2 FXS Ports) Call (650) 282-2885 for instant "REBATE" (and) with any Pre-Sales questions! We are a Yeastar sub-distributor (approved by Cherry) We are Asterisk Specialists and IP PBX Telephone System professionals! We can help with rollout & installation (support packages available) IMPORTANT: See the production description for specifications on the equipment!