Shenzhen SD Technology Co., Ltd is one of the mid-scale enterprise and specializes in designing, manufacturing and selling of Patrol Hawk series of GSM alarm system. Patrol Hawk Security is the trusted name in wireless home security. Many homeowners today live in density housing and strata blocks, which limits hardwired home security. Whether you rent, lease or in temporary housing, the Envoy Wireless Home Security Package from Patrol Hawk provides the perfect solution in home security. Having safely secured thousands of people with our state of the art alarm and monitoring packages, you too can benefit from the expertise at Patrol Hawk and have real peace of mind knowing your home is in safe hands. Today our main products include: GSM Home Alarm System GSM MMS alarm system GSM Industrial Alarm System GSM Car Alarm System Telephone Line Alarm System GSM Monitoring Center Most of our products have approved by FCC & CE. Until now, we have owned 1400 distributors in 20 provinces across China. Also, the oversea market is also developing in a rapid way.