Rhino Tuff™ Puncture Resistant Orthotic Insoles meet the puncture resistant specifications for protective footwear outlined in the ANSI Z41-1991 Standard, Section 5.3.2. This section states that the puncture protective device shall withstand a minimum force of not less than 270 pounds to penetration when tested in accordance with Section 5.4 of the ANSI Z41-1991 Standard. Underwriters Laboratories, Inc. (UL) has tested our insoles for resistance to penetration using the test method outlined in Section 5.4 of the ANSI Z41-1991 Standard. Results indicate that our insoles are capable of withstanding 322.1 pounds to 337 pounds of force.