Kitagawa 8014 601SP Carbon Dioxide Gas Detector Tubes Latch Catch This tool comes with a barnacle buster This tool comes with a 20" bar & chain The wavy pattern cut from the top of the blade (created by a fireman from Sweden) and along the inside of the handle let you place a piece of rope (between the half open blade and handle) and scissor the blade shut especially convenient for cutting rope in and around flesh without having to fully open expose the knife's blade The length of stain is normally read directly off a scale printed on each tube The reaction causes a colorimetric stain which varies in length to the concentration of the gas or vapor being measured