There's something new in Australia that is unique in that is is not infra-red, so it DOES see around corners. The EV Alert coded UHF signal (adjustable from 0-40mtrs(0-130ft)) activates any device, receiver on wall, speed delimiters, it opens doors, sirens, flashing lights. In addition you can include a personal pager unit that buzzes & vibrates. The VHF unit has a range of 0-500mtrs) Has applications for trucks, trains, forklifts, you name it. evalert.com.au
This is ONLY to be used to report flooding, spam, advertising and problematic (harassing, abusive or crude) posts.