Ideal for the Sales Professional or Technician. Fleet Trade Gauge has a go no go indicator for wide or standard brakes. Each end has a 50% indicator depending if the linings are wide width or standard width. If the indicator end does go in between the linings, then you have 50% or more lining left. If the indicator does not go in between the linings, then you have less than 50% of lining left. This tool does not give an actual lining remaining.