The traditional Vietnamese national dress is known as ao dai and in its modern form, it consists of a log-sleeved, tight-fitting tunic, that is ankle-long and split open on both sides from the waist down, and with a slant row of buttons or hooks, that run from the right side of the neck to the armpit and further down the side. The tunic is usually made from silk, and worn over a pair of loose trousers.