Made of waterproof and abrasion-proof nylon fabric, which can better protect the contents of the bag from being wet by rain. The abrasion-proof feature ensure that you can use a new fanny pack every day. The strap is adjustable, designed for men and women of all waist sizes, fits waists from 24" to 50". It is very easy to adjust the strap so you can have it as loose or snug as you like, even can be used as a shoulder bag.