Tom 3.5 SATA Hard Drive or you can purchase a solid state drive that is more expensive and then purchase the 3.5 shell to plug it into the camera system.

Tom Yes it is compatible with android. I would first recommend round file the mouse they supply you and use another mouse and plug it into the front of the camera system box. Plug in the camera system box using a network cable to your wireless network hub. Connect a monitor using a HDMI cable. Do all of this before downloading any apps and turning on the system for the first time. Everything else will be pretty much self explanatory through the cryptic instructions.

Tom You can purchase a 2TB 3.5 SATA Hard Drive and with will fit just fine. I installed the 1TB Western Digital that cost $29.95 at Best Buy.

Tom There is no recording audio or microphone in camera. 1080p only with motion detector and night vision.

Tom Do yourself a favor and order a Western Digital 3.5 SATA 1TB Hard Drive for $49.95 at Best Buy or Office Depot/Max. I installed on and it worked perfectly.

Tom No it does not. No microphone or speaker in the camera. You can set up the motion detector to alarm you if there is movement but I have not been able to get the system to email me when the alarm goes off. I set up the email profile but so far I have not been able to get an email to send. The smartphone app works fine and you can pull up a message through the app that there was movement but will not send the video of the movement because this system does not have cloud support.

Tom Still waiting to receive mine from China. I'll let you know when I figure it out.