- PATENTED MEASURING TECHNOLOGY: Ruler and protractor in one for measuring inside and outside angles with precision. - BLACK RULER, WHITE SCALES: High contrast scales for easy reading of length and angles. - HIGH ACCURACY: Angle accuracy within ±0.3 degree. A suitable choice for most projects including woodworking, crown molding, and daily use. Folded length: about 7.5 inch / 220 mm. Total length: 400 mm. - LOCKING FUNCTION: Angle finder can be locked at any angle for stable, hands-free measurements. - WHY YOU NEED IT: Combines quick angle capture, repeatable readings, and compact storage for on-site and workshop use. - USE SCENARIOS: 1) Woodworking and crown molding: measure and transfer inside and outside angles for precise cuts. 2) Cabinetmaking and furniture assembly: align joints and miters with a stable reference angle. 3) Home improvement and DIY tasks: check frame angles, install pictures, and align windows or door frames.