In this video, Barb Bolle (the inventor of the Shot Glance Rulers) gives a brief run down of how simple and effective this bar inventory system is to use to keep track of your bar’s inventory. You can purchase Shot Glance Liquor Inventory RulersĀ on Amazon. These rulers are a great addition to any inventory system for bar owners or managers especially when they are catering or setting up temporary bars for special events.