Vollebak, the same clothing company behind the world's first graphene jacket, has developed a pair of trousers built to outlast every item in your closet. The 100 Year Pants promise to be tough enough to endure in the harshest conditions, and soft enough to wear while loafing around your home.

As Fast Company reports, the secret to the 100 Year Pants's durability lies in their three-layer design. The outer later is water-resistant and can stand up to decades of wear-and-tear, while the innermost layer is made from a synthetic material that doesn't burn or melt. In between is a fireproof layer that automatically expands when exposed to extreme heat, creating a barrier between your skin and the flames. The pants are also outfitted with four spacious pockets, adjustable ankle belts, and leg vents you can zip open on hot days.

The material was originally designed for soldiers, and it's manufactured in Switzerland. But unlike typical military or space gear, the 100 Year Pants work just as well as lounge wear as active wear. The outer layer feels like sweatpants and the inner layer feels like cotton on your skin, while the fireproof middle layer allows the garment to breath. The pants are also designed to stretch with your body whether you're climbing a mountain or practicing yoga.

Vollebak has experience designing clothes meant to last longer than the average wearer. In 2017, the company released its 100 Year Hoodie, made from a softer version of Kevlar, for $300. At $645, the 100 Year Pants are an even more serious investment, but they may be worth it if you plan on making them the last pair of pants you buy for awhile.

[h/t Fast Company]