Additional long-range SIP cordless base station Up to 12 floors in-building penetration, 250,000 sq. ft. of facility coverage, 3,000 acres of property, open land coverage Base supports up to 4 concurrent calls (4 SIP or 3 SIP + 1 PSTN) Works with any IP-PBX that supports the standard SIP protocol Independent 2-way intercom "Push-to-Talk" (PTT) broadcast feature Proven durability with ruggedized design