The Harmony Dual-Arch Tray from Ho Dental can capture the prepared teeth, the opposing arch and the bite registration, as well as the facial midlines, all with one device. Can be used without alignment sticks for single units, or with alignment sticks for multiple units. To capture the midline and horizontal plane, simply syringe a small amount of impression material into the receiver area, and hold the cross in alignment until set. Even with this added convenience, Harmony trays are actually less expensive than using a separate triple bite tray and an alignment device. Made from biodegradable, renewable cornstarch plastic. 40 trays and 40 alignment stick sets per package.