Universal security DVR designed for use with 2MP/5MP HD TVI, AHD, CVI, RS485 PTZ, analog and IP cameras. For optimal performance, use this DVR with TIGERSECU security cameras. This DVR does not include a pre-installed hard disk drive. For continuous local recording, install up to surveillance hard drives of up to 16TB. Compatible with WD Purple, Toshiba and Seagate surveillance hard drives. This DVR does not work with external hard drives. Remotely access and play surveillance footage and control the security DVR with no contract or monthly fees with TIGERSECU's HD Viewer. For optimal performance, 1 Mbps upload speed is recommended for each 1080P camera. Bitrate settings can be adjusted in the DVR to accommodate slower network speeds. Mobile app requires iOS 9.3 or later and Android 9 or later. Compatible with iPhone and iPad. High efficiency video compression enables you to record more footage for the same storage space. No fan noise and a quieter system with our unique heat