U.S. Military Individual Equipment Belt, also known as a pistol belt or ALICE (All-purpose Lightweight Individual Carrying Equipment) belt. It is designed for military personnel to carry individual equipment. 
Key features:
Made of olive drab nylon webbing with metal or plastic hardware. 
Adjustable in length using adjusting clamps. 
Equipped with slide keepers (also known as ALICE clips) for attaching pouches and accessories. 
Eyelets for suspenders and M-1910 double hook attachments. 
Features a quick-release buckle for easy removal. 
Available in medium (for waists under 30 inches) and large sizes. 
Used to carry items such as ammo pouches, canteens, and field packs.