Two-Step 3D-BionicSphere (R) system under front waistband. 3D Bionic Sphere (R) system at tailbone panels. Air-Conditioning Zone (R) ventilation system on inner thighs. Air Guides (R) aid the Air-Conditioning Channel (R) system in circulating air. AirConditioning Spot (TM) ventilates back of knee. Enlarged ISO-Pad (TM) targeted insulation hip panels. Insulation panels on upper thighs. ExpansionKnee (TM) protect knees from the cold. ISO-ClafPad (TM) delays the cool down of calf muscles. Made in Italy . Size S = S/M . Size L = L/XL