ZAP™ dual arch fluoride gel trays are for full coverage of interproximal and occlusal areas to gingival line. Closed cell 4 pound foam assures goad, strong, rigidty - increases patient comfort while minimizing gagging reflex. Convenient, flexible handles simplify filling and placement of tray. Available in 3 color-coded sizes - small (yellow), medium (white), large (blue). Supplied in unique, stackable "space-saver" package.