Spandex training shorts made in Poland and used by several countries including Poland, Georgia and Kazakhstan — among others. These shorts come with a thicker piece of fabric on the thigh to provide some level of protection against sharp knurl and tearing. While no fabric can withstand knurling forever, this extra protection should help to avoid knurl-caused holes for a lot longer than you’d experience with garments made with just spandex.
The size chart is approximate and you should adjust your size up or down depending on if you have thicker or thinner legs for your weight. As an example, a 5’7″/170cm athlete who has thick legs and weighs 105kg/231lb will not fit in a pair of size XL — 2XL will be necessary. If you’re a 105 and tall, the XL will probably be fine. Similar advice applies for all classes — if you’re tall with skinny legs for your weight and near the border, size down. If you’re short with thick legs for your weight and near the border, size up.
Larger athletes (above 130) will probably not fit very well in the 3XL unless they have smaller than normal legs and waist for their size.