penetration resistance is a great asset when we are working with sharp materials. During regular shoe production there is little more that can be done, but S3 and S4 have additional puncture resistant material on parts of their sole, ensuring that dangerous objects do not pierce through. This gives you more protection than usual shoes against sharp nails, broken glass and other penetrating objects. The fact that they don’t need to be oiled means they last longer than any other safety footwear out there today too! S3 – All of the features as S2, plus midsole penetration resistance meaning that these shoes are puncture proof. For example, a steel midsole prevents sharp objects from piercing through the sole.