... to operte ,just press one button ,see the video Door bell function ,peephole +door bell Don't disturb , ... adjust melody .16pcs melody for option Can press monitor button by 1500pcs at least per 3pcs ... . When in “don’t disturb “ function ,anyone press call button ,indoor display have no door chime sound . ... Put 3pcs AA battery in peephole viewer ,then press in base flange Following is real pictures of ...