Technical characteristics The “preventive 140 Hostess” tights are made of smooth knitted lycra and features a reducing low-cut bodice. With its 140 denier structure, it offers strong compression that constantly massages and tones the legs with decisive tenacity. In addition, all Silca tights are purified with BIOSETIFY, an essentially natural treatment for Silca's exclusive worldwide use. Why are they useful? Compression socks are essential for those who spend many hours standing or sitting, such as flight attendants. These socks, with a strong graduated compression of 18-20 mmHg, are designed to relax, massage the legs and alleviate the tiredness of the day.