S-Mount on September 29, 2015 | Marketing Team The S-Mount is a desktop or surface mounting kit for the HKB-2X Speaker Station. It is easily adjustable to several angles for better viewing. Use our Digital Partyline Calculator to calculate the maximum acceptable cable length for a Clear-Com Digital Partyline System. S-Mount Features For use with HelixNet HKB-2X Speaker Stations Connects to HelixNet Main Stations over a single shielded twisted-pair cable Powered by Powerline, third party Power-over-Ethernet (PoE) or AC/DC universal power adapter