Guitar gap ruler 1. Used for easy to measure the gap width 2. The decimal and metric size laser etching on each blade 3. Each blade is made of quenched and tempered steel 4. The blade protector has a thumb incision for easy removal of the blade 5. Suitable for measuring metric clearance between two objects or parts 6. A magnetoresistance air gap for an electronic ignition system requiring a Non-ferrous metal blade 7. Size: 95 x 13 x 10mm 8. Gross weight: 150g