Customize and sell downloadable PDF vouchers for products. Connect Your Business and Online Store with Customizable PDF Vouchers. While virtual gift certificates are great, they limit many business owners who want certificates that can be redeemed at a physical location. Tired of the disconnect between selling online and your on-the-ground business? The PDF Product Vouchers extension solves this problem for you! Now you can customize and sell downloadable PDF vouchers for products such as tours, events, classes, and lessons; the possibilites are endless!