... and installation 3 3rd generation digital peephole viewer 4 door thick 25-110mm 1.Private mold,fashion Design ,digital Peephole Viewer 2.Photo-snapping and door bell 3.3.5 inch ... EXTENSION SPARE PARTS, SUITABLE FOR DOOR THICKNESS FROM 25~110MM!! 3.5" with door bell, video record, photo snapping,2.0M camera, digital Peephole viewer!! digital door camera