Accuracy is good, however the cast nameplate protrudes out of plane making line transfer to the adjacent surface wobbly and inaccurate. The base of the level is half the width of the center of the level and rides on two small (about 1/4 inch) ridges separated by a V-groove that holds the magnets. The center width prevents you from laying the spirit level less than approximately 3/4 inch wide. The magnetism is sufficient. Idiot design. Get Stable.