Gentlemen, CHENGDU HI-TECH CRANE SAFETY CO.,LTD is the manufacturers of CXT/30A Anti-Collision and Zone Protection for Tower Cranes The function of this CXT/30A Anti-Collision and Zone Protection System is to automatically and simultaneously control and deal with two major construction site problems by computer, interference between tower cranes in a multi-crane site and the protection of no-go zones. The system can provide real-time supervision and monitoring of up to 9 tower cranes in one single sited and, if need be, keep operational records for future safety review and inspection. The system will let the crane operator to always safely operate the tower crane with the highest efficiency. It continuously computes the relative locations of jib-arms and trolleys of the tower cranes within the network that might interfere with each other. This site network connects all local networks of tower cranes on site with the CXT/30 Anti-Collision and Zone Protection System central control unit industrial computer Pll-500, installed at site office. Another tower crane can be added to (maximum: 9 units)and/or taken off the site network at any time. If you are interesting please contact me at anytime. Best regards Jim zhu