- NELON Door Viewer - Heavy Duty & High Security Product Specification - Door Hole Diameter: 14mm (for 28mm face) , 28mm (for 38mm face) - Door Thickness: 35-60mm (for both) Product Description: - Door viewer comes with cover - Clear glass lens ensure a clear view of people / things behind the door or in the outdoor environment - Modern peephole for your home! Size (diameter) available: 28mm and 38mm Colour available: Silver and Antique Brass Price shown is the starting price; other colours/sizes are priced as listed by NELON. WhatsApp 9898 9268 to confirm your option.