My name is Steven Martin, President of SlabDoctor International, Inc. We manufacture the worlds' longest aluminum digital levels right here in the USA. These Patented levels can be used by every Tradesman in the residential, commercial & industrial Occupations. These are Specialty Tools; and there is a Market for them. To see a SlideShow of our Product, please click on: http://s1103.photobucket.com/albums/g479/SlabDoctor/?albumview=slideshow ; this gallery of photos will simply amaze you. We offer Multiple Piece Level Sets, 3 sizes: our 3-Piece Set is 12foot long; our 4-Piece Set is 16foot long, and our 5-Piece Set is 20foot long. All Patented and MADE IN THE USA.