The #69 & #912 are both center ruled and regular ruled for added flexibility. The #34 Guaging Square is a fan favorite and ideal for keeping in your back pocket to gauge squareness and check depth on a multitude of task in and out of the shop. Perfect for setting router, table and circular saw depths, as well as for opening your favorite bottled beverage. Stainless steel. The model number relates to the length in inches of the tongue and body. Available in decimal inch and 16th inch scales.