The Comfort Business Socks have, in the last year, had a change in composition to incorporate 28% Tencel yarn. Tencel fibre is very similar to bamboo fibre but it is made from hardwood and maintains its strength much better under moist conditions.The socks still have the same feel qualities as the Extra Thick Socks in terms of their anti-static and anti-bacterial properties but they are not as thick. The Comfort Business Sock, with padding on soles, toes and heels, is designed for everyday business wear.