This kit was designed to provide an objective way to classify and measure colour of roasted beans. The kit ncludes a light-weight vinyl binder, with 8 colour disks. These have been numbered in 10% increments starting at "very light" (tile #95) to "very dark" (tile #25). Also included are 2 black background sheets, 2 standard petri dishes for sample preparation and an easy to interpret manual from Carl Staub. As we've all experienced, colour can be interpreted and expressed in many different ways (and shades); this is the industry standard meant to reduce that inconsistency, and allow consumers and toasters to agree on their degree of roast.