General Tools 823 Digital Angle Finder Rule, 10-Inch (254mm) Stainless Steel Protractor in 32nd and MM Increments, Large LCD Display, Measures 360 Degrees PREVENT WASTE- This digital 10 stainless-steel ruler and angle finder combination tool makes precise, easy and fast measurements LOCK IT AND REVERSE IT- Digital protractor has lock and reverse angle functions. Place the angle rule where you need to measure your next cut, LOCK it in place with knurled locking nut, make a mark and use your miter saw to make your cut. The angle finder will automatically display the reverse angle MEASURE 360-DEGREES- Hinge mechanism on the angle rule allows a full range of 0 to 360-degrees to measure inside outside and reverse angles, accuracy +/-0.3 Degrees. Center check notches are on the ruler ends enables exact ruler placement marking. Display has a hold function to freeze movement for accuracy PICK YOUR ZERO POINT- Woodworking tool can be zeroed at any point in the swing plus the display can be inverted for easy reading LARGE LCD DISPLAY- Easy to read LCD display eliminates guessing or eyeballing the angle and length with one convenient protractor tool