Constructed with a durable nickel-plated steel, this heavy duty roller buckle is perfect for use in various applications, such as fashion and utility belts, leathercrafting, purse and bag making, and shoe and boot manufacturing and repair. The double-tongue adds a design flare and keeps the wide strap secure. The 3" buckle works with 3" straps and the 4" buckle works with 4" straps.