Natick Labs designed the tropical combat jacket and trousers in 1962 following a request from Army Material Command for a specialized uniform for Special Forces personnel in Vietnam.1 The trousers were made from OG-107 wind-resistant cotton poplin and had two side hanging pockets, left and right hip pockets and two bellows-type cargo pockets that contained leg ties. The left thigh cargo pocket also contained a smaller inner pocket that was originally designed to hold a survival kit. The trousers also boasted a gas flap behind the button fly, leg bottom drawstrings and waistband button tabs that allowed the waist size to be adjusted by two inches.
The tropical combat uniform was ideally suited to Vietnam because it was both lightweight and quick drying, but itis exposed pocket buttons had a tendency to get snagged in the jungle.
1. Support To United States Army In Vietnam - Clothing & Equipment (United States Army Material Command Feb 1967)