The GSC3505 is a 1-way public address SIP speaker that allows offices, schools, hospitals, apartments and more to build powerful public address announcement solutions that expand security and communication. This robust SIP speaker offers crystal clear HD audio functionality with a high-fidelity 8-Watt HD speaker. The GSC3505 supports Bluetooth devices, a built-in whitelist and blacklists to easily block unwanted calls, SIP and multicast paging, and integrated dual-band Wi-Fi. By pairing the GSC3505 with other Grandstream devices, including desktop and cordless IP phones as well as the GDS series of Facility Access products, users can easily sculpt a state-of-the-art security and PA announcement solution. Thanks to its modern industrial design and rich features, the GSC3505 is the ideal SIP speaker for any setting.