Features:Designed for a variety of compact products.Integrated USB to serial port chip, can be debugged directly by plugging in the computer.SIM800C can be used globally and can realize the transmission of voice, SMS information and data information with low power consumption. USB to GSM is a quad-band GSM/GPRS module with stable performances, compact appearance and high cost performances, which can meet the various need of customers.USB to serial port chip, easy to install and high compatibility.brand new and high quality Specifications:Material:ABSLength:Approx.53.5mm/2.1inches Note:1.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package includes:1 Set USB to GSM Module