11oz stretch denim (cotton 97%, elastane 3%). Reinforced with 100% Authentic DuPont KEVLAR aramid fibres on Seat,Thigh and Knee impact Areas. DuPont and KEVLAR are registered trademarks of E.I. Du Pont de Nemours and Company. Suitable for daily use. Stretch shirring panel above the knee and waist-back for better movement. Easy insertion of knee protectors from outside. Non-shrink treatment. Fully machine washable.