This is a cover to allow you to blank off the switches on a standard UK light switch (with 1 or 2 switches). This is perfect if you've gone down the home automation route with smart bulbs (e.g. Philips Hue or LIFX) and want to make sure no-one turns the lights off at the wall by accident! This also gives you the ideal place to mount a battery operated z-wave button controller or the Philips Hue "Tap" controller.
Requires four self adhesive backed neodymium magnets to attach to the light switch faceplate. Magnets must be no longer than 20mm and must be 1.5mm thick; they can be any width up to a maximum of 10mm. You can use 10mm diameter round magnets or up to 20x10x1.5mm bar magnets - whichever you prefer. Just fix two of them to the cover, and the opposite two to the light switch face plate, and the magnets will then adhere to each other to hold the cover in place over the switch. Important reminder - you need two magnets with the adhesive on the SOUTH pole side, and two magnets with adhesive on the NORTH pole side for this to work.
Alternatively you can use blu-tac (or similar) on the indendted sections of the two centre tabs on the iside of the cover where the magnets would attach to, and just stick it in place with that (which works just as well!)