DSS4004-S2An Economical Surveillance SystemCost-effective> Preloaded with linux-optimized easy-to-use DSS Express, which makes the deployment simplified> Pre-activated 256 video channels can save the enormous costs of projectsHigh Reliability> Long-term stability test makes the hardware, OS and software more compatibilehttps://dahuasecurity.s3.ap-southeast-1.amazonaws.com/uploads%2Fsoft%2F20210804%2FDSS4004-S2_datasheet_20210723.pdf