I dont understand why all these door knobs are designed in such a way that one has to cut out a chunk of their doors in order to fit something that can be designed with a less demanding/intrusive built. This could be really designed with a 10mm hole for a pin to go through instead of having to drill a freaking window into you door . Everywhere one looks there's space for innovation. (I guess most people don't care whether they have giant holes drilled into their doors)