Spyholes, or door viewers, cater to an essential need for security and privacy in one's home or office. These ingenious devices are typically installed on entry doors, allowing individuals to discreetly view who is outside without the need to open the door. They function as a small-scale peephole that offers a wide-angle view, which is particularly important for individuals concerned about unsolicited visitors or enhancing their home security measures. Their use is straightforward - one simply looks through the viewer to observe the area outside the door. They're an integral part of home security systems, commonly used in private residences, apartments, and businesses seeking to monitor and control access.

In terms of brands and product offerings, customers have a variety of choices in selecting the right door viewer to suit their needs. Abus offers the DTS3214, a product that ensures clarity of vision and security. Upgrade to a more technologically advanced option with PrsTech's Digital Door Spy, which integrates digital capabilities for a clearer and often broader view. Yale's Door Viewer is another reliable choice, promising the durability and trust that comes with a renowned brand. Werkstarck elevates the standard with its Door Viewer Spies, which are characterized by robust construction and optical quality. Lastly, Rieffel 's Dts-standard offers solid performance for those seeking a fundamental, yet effective door viewing solution. Each of these products may come with a range of features, such as different viewing angles, construction materials, and even digital enhancements, allowing for customization based on personal preference and safety requirements.