... good shockproof performance;4. Our regular size is 17", 19", 21", other size can be customized; ... , RS232/RS485 connectors are equipped;8. This LCD lift can be used with conference table& computer desk ... good shockproof performance;4. Our regular size is 17", 19", 21", other size can be customized; ... , RS232/RS485 connectors are equipped;8. This LCD lift can be used with conference table& computer desk ...