Amp up your look by wearing the Marc Jacobs The Biker Nylon Belt Bag. The stylish yet sporty bag has a double-layer design with a zipper closure. It has a brand logo patch at the front that compliments the overall look. The adjustable belt loop allow Nylon construction. Amp up your look by wearing the Marc Jacobs The Biker Nylon Belt Bag. The stylish yet sporty bag has a double-layer design with a zipper closure. It has a brand logo patch at the front that compliments the overall look. The adjustable belt loop allows a custom fit. Nylon construction.