Bamboo Fibre Brief Introduction These JINSHI briefs are made of bamboo fibres which is superior to cotton. Smooth, lighter in weight, and easy to care for(washer/dryer, no wrinkles, durable). Japanese scientists have found that bacteria which on the bamboo fiber products will be killed about 75% after 24 hours. Bamboo fabric has insulating properties, helping the wearer stay warmer in winter and cooler in summer. It also ensures human and eco health-bamboo plant is organically sustainable, grows naturally without chemicals. Item Feature Smooth & comfortable & breathable & lightweight & supportive & soft & dries quickly Item Size Map(Waist Measurement): US M(27inch-30inch) US L(31inch-34inch) US XL(35inch-38inch) US XXL(39inch-42inch) Item Garment Care Hand-wash or Machine Wash