The device has an accuracy of about 0.1 degrees. I was able to compare this unit to two other digital levels on a flat, hard surface. All results differed within 0.1 degrees. The numbers are large and well lit with the ability to toggle from degrees to percent or mm/m. This saves arithmetic operations. The side output of the laser is very convenient for marking the drilling locations at some distance from the spirit level position. Unlike most similar devices, the battery is rechargeable and big enough to get you through any reasonable work day. My only complaint is that I wish the manufacturer had provided a cloth sleeve for protection during storage.