Features:Door Opener: This is a powerful access controller for access control, door control, remote device switching and parking systems.Practical: It can be used in locations where you need to open/close systems, machines or equipment remotely via a free call from your mobile phone.Safe and reliable: use caller ID for identification and ignore unknown-calls; operate from anywhere with no distance restrictions; add or remove users via commands; no need to provide remote control for different users.Relays switch: for connecting door or machine switches; relays will return confirmation to you, this function can be operated by the user.Satisfactory service: If you have any questions, please contact us promptly. We will provide you with better quality products and services.Notice:1.Actual color may be slightly different from the image due to different light effect2.Please allow 1-3cm deviation due to manual measurementDescription:Frequency band range 850/900/1800/1900MHz.Voltage input: DC9V-30V/1ARelays type: 3A/250VAC,20A/14VDCRelays type: NO/NCRelays time: 0s-95sNumber of users:200Connection switch: SupportCommunication specifications: 2G