The tool consists of three chart; the chart used to determine the TLV is a function of the lifting duration and lifting frequency. Then, based upon the one of four categories for height of the lift (floor to mid-shin height, mid-shin to knuckle height, knuckle height to below shoulder, and below shoulder to 30 cm above shoulder) and one of three categories of horizontal lift distance (close, intermediate, and extended), a TLV for weight is given. In some cases, the tables indicate that there is no known safe limit for repetitive under those condition.