The RED 1 uses the same patented A.R.T. (Auto Ranging Technology™) as the MODEL 1 but it offers higher accuracy, resolution and longer battery life. It also offers the ability to measure absolute pressure. The Winchester Engineering Red 1 is the first and only digital gauge capable of spanning from absolute vacuum to 20,000 kPa while maintaining an outstanding 0.05% of Reading throughout. With this new and improved accuracy and large and vibrant SMART display, it puts the MODEL RED 1 truly in a league of its own!