A small safe in approximate binder or photo album size with an electronic keypad that is flush with the surface, so I can turn the keypad against a (closet) wall and it will not look like a safe. How about a 'push to open' lid over the keypad to hide it? My own preference would be white because it is less conspicious. Me, I would tape a KeySmart SmartCard AirTag to the inside ceiling with white tape. It might send normally, but it might also send when the safe has been opened somewhere else. Small size for passports, credit cards, jewelry, etc. Inside padding option, yes. How about a complementary sleeves or self-adhesive sheets to attach, like grey or rainbow colored? 🙂 Notification beep when battery is running out. Could also come with an always connected power cable. If the cable gets detached then an alarm goes off. (Note that this would happen during power outages as well). Having keys to hide/place at a neighbour is a hassle.