Please note: 1.please use at least 12V2A power adapter connect this board,power adapter is very important,make sure your power adapter is in . if you connect with 3T or 4T HDD,please better connect with DC12V3A or 12V5A power adapter. 2.the DVR display resolution is default 1920 x 1080P.If you use a monitor to connect this device, please make sure it can withstand 1920 x 1080P resolution input. or the monitor will show black screen after it display first time the Boot logo(will show "out of range" or "input not supported") 3.You need to that your monitor resolution can support my device resolution output or support adaptive mode, or you can try to not adapt to the monitor, directly connect to , and then use or APP: xmeye to search for the device and use it. You can also tell us the resolution of your monitor before you make order, and we will adjust the resolution output . 4.The device built-in battery, which is used to save and update the time. When there is no power, the time can be saved, but even without this battery, as long as is connected, the time will still be updated.for some country,built in battery maybe can not send,So if it returned back due to battery, I hope you can agree send without battery,thank you. 5. Please be careful during operation and take anti-static measures to avoid damage to the circuit. For each product, we will test and a video before shipping, confirm that there is no problem before shipping. We are not liable for damages deemed to be caused by improper operation. Color: green Material: PC+metal What is coaxial Audio: it is mean camera which support coaxial audio connect to DVR which support coaxial too,can No need other device can hear voice from camera by Smartphone or Computer What is Audio over coaxial function 1.it is a nction that the coaxial audio camera connect to coaxial DVR only by BNC cable,then can transfer sound and can hear sound from smartphone.No need add sound pick up device. 2.you can add one speaker,or add a monitor which built in speaker,then you can hear sound, 3.you can add a microphone or use smartphone,connect App of the DVR and talk. 4.must make sure your camera support Coaxial audio and must work for Xmeye coaxial audio dvr,some brand coaxial audio camera not work for this DVR Package Contents: 1 x DVR motherboard Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.