American National Standard for Hand Protection Classification, covering impact resistance in work gloves. 

The performance level of the glove shall be classified against the performance levels in the table below. The difference between levels is measured by Kilonewtons (kN). The overall performance level of the glove is determined by the lowest performance level recorded.

The impact sites are located on the knuckles, the fingers and the thumb.

NOTE: For example, if the fingers and thumb are rated as performance level 1, but the knuckles are performance level 2, then the entire glove is rated as performance level 1.