AHD DVR Hard Drive Disk InstallationStep 1 Loose the screws which are fixed on the box coverStep 2 Push and remove the coverStep3  Connect the hard drive to the DVR SystemStep 4 Fixed the Hard Drive Disk onto the box.Put the cover back to position and fixed the screws.Note that DVRs we sell do not include hard drives. You need to buy by yourself.   You can buy a nice DVR by this link: https://www.ansice.net/collections/dvr-nvr/products/hybrid-dvr-1080n-video-recorder-audio-1-ch-h-264-ahd-tvi-cvi-nvr-4-in-1-dvr-for-ahd-tvi-cvi-coaxial-hd-camera-xvi-coaxial-control-ip-camera-8-ch

H264 DVR NVR storage schedule 720p Cameras:24G/Day/Channel; 960p Cameras:30G/Day/Channel; 1080P cameras 76G/Day/Channel. Hard  Disk Capacity Storage time Numbers of cameras 720P 1MP 960P 1.3MP  1080P 2MP 500G 4 5 DAYS 4 DAYS 1.5 DAYS 1T 4 10 DAYS 5 DAYS 3 DAYS 2T 4 20 DAYS 16 DAYS 6 DAYS 3T 4 30 DAYS 24 DAYS 9 DAYS 4T 4 40 DAYS 32 DAYS 12 DAYS   Click this product link to see a nice AHD TVI CVI CVBS NVR all 5 in 1 DVR

Ansice ACB601 AHD Camera 2MP 1080P 4MP 2k 8MP 4k AHD TVI CVI Night Version 3.6mm 6mm 8mm lens