... telephone the most professional manufacture in Asia Seaside telephone, anti-explosion telephone, dust proof telephone KNSP-11 Applications: As Public ... available Matching with most PABX, PBX and PAX systems Features: 1. Aluminum alloy die - cast body, Vandal resistant and tamper ... (A)Standard frequency697. 770. 852. 941Hz Seaside telephone, anti-explosion telephone, dust proof telephone KNSP-11