After having initial problems fitting this item and spoke to technical support, it appeared the installation instructions were incorrect. One stage was out of sequence. After solving that problem the install was completed very easily. This item has given me peace of mind as I can see who is at the door without having to open it, and as a more elderly couple you can not put a price on this safety measure. We have a long drive and you can see the full length of it with this little lens, which is mind-boggling. We would recommend this product