Two Most Popular Gauges Used in the Setup Process for Electric, Acoustic, Classical and Bass Guitars in One Combo Pack Precision String Action Gauge with accurate measurements that are easy to read with the black finish contrasted with deep etched white markings. We include measurements in inches, metric & 64ths to customize to your preference. Our convenient chart on proper height by instrument type takes out the guesswork. String Action Gauge includes Pickup Height Ruler to Dial in your pickup sound . Precision Stainless Steel Truss Rod Gauge Includes the 3 Most Common Truss Rod Neck Relief Measurements (.006", .008", .010") for Electric, Acoustic, Classical & Bass Guitars with Easy to Follow Instructions Printed Right on the Handle & an Innovative Pick Capo to Assist These products are part of our KEEP IT SIMPLE, SETUP (KISS)™ Method using our Precision Gauges & Tool Sets combined with step-by-step general guidelines anybody can follow and setup their guitar to play and sound great.