Nothing is reliable like a DeWalt box beam level. No fancy technology is required for these simple tools to provide accuracy within 0.0005", even when working in less than savory conditions. Anything can happen on the job site, which is why these levels feature 5x reinforcement, providing extra strength that other levels dream about. Competitive levels are practically disposable, but not these; on top of their reinforcement they also have unbelievable shock resistance courtesy of the robust metal and over-mold end caps. Like all of their tools, these DeWalt levels are Guaranteed Tough.