Gsm sim900a dual

* 8 ports SIM card slots.Just like 8 single-channel equipments work at the same time * 2G GSM Frequency: 900/1800MHz * SMS sending: 600/800/1000/1200 SMS per hour by one port * Connection with the computer through RS232 interface (PCI card is opitonal) can be integrated with USB interface * Each port with separate power switch * Each individual module can be discharged * Bulk sms/mms sending, voice ads, data consumption and IMEI changeable etc * Open AT command * Industrial chassis, elegant shell * Wireless access to interne * Comply with GSM phase2 standard * Internet Services: PPP,TCP, UDP, FTP,HTTP, SMTP, POP3 Model NO. : QS81 Module : QS80 Network : GSM Frequency : Dual band: 850/900/1800/1900 Mhz Max Transmit Power Class 1(1W):DSC1800,PCS1900 Class 2(2W):GSM850,EGSM900 SIM Port : 8 x SIM card(big/small) slots SMS quantity : Send 600/800/1000/1200 SMS per hour by one port SIM port : Big card:85*53mm , small card:25*15mm, 1.8V or 3V Port : USB2.0/PCI Function:Bulk sms/mms,voice,wap,imei change,stk recharge,CSD,etc. Internet : Wireless Access to internet With TCP/IP stack Internet Services: PPP,TCP, UDP, FTP,HTTP, SMTP, POP3 AT command PC System : Windows2000,Windows XP,Windows Vista,Windows 7,WinCE 4.2,WinCE 5.0,WinCE 6.0,Linux,MAC Input voltage DC 12V~24V Working temperature -20℃~+70℃ Storage temperature -40℃~+85℃ Size : 220*120*114mm Package size : 27*21*17.1cm Housing : Aluminum Casing Weight :3.0kg Accessories :AC/DC adapter, USB cable/PCI card, Antennas and driver

HSDPA show contact info - LTE B1 (2100) B2 (1900 PCS) B3 (1800 +) B4 (1700/2100 AWS 1) B5 (850) B7 (2600) B8 (900) B20 (800 DD) B28 (700 APT) B38 (TD 2600) B40 (TD 2300) Dual SIM (Nano-SIM, dual stand-by)> (ensure to check compatibility with your carrier before purchase) 6.3 inches 1080 x 2340 pixels, 19.5:9 ratio (~409 ppi density) - Fingerprint (rear-mounted) 64GB + 4GB RAM - microSD, up to 256 GB - Qualcomm SDM665 Snapdragon Octa-core - Non-removable Li-Po 4000 mAh battery Rear (Main) Camera: Quad 48MP(wide) + 8MP(ultrawide) + 2MP(dedicated macro camera) + 2MP - Front Camera: 13 MP, f/2.0 - Video: 2160p@30fps, 1080p@30/60/120fps, 720p@960fps Unlocked cellphones are compatible with most of the GSM carriers (Like T-Mobile or AT&T) but please be aware that are not compatible with CDMA carriers (Like Sprint or Verizon Wireless for example) - FCC ID: 2AFZZC3JG click here click here https://www.amazon.com/Xiaomi-Redmi-Factory-Unlocked-Smartphone/dp/B07YJHXZT6/ref=as_sl_pc_tf_til?tag=habbu4150b-20&linkCode=w00&linkId=bb41c4870ce93523ff2515eb98b392be&creativeASIN=B07YJHXZT6