Swiss Tech Aluminum Levels have a rigid aluminum frame which assures durability and accuracy. Top read window for easy readings, cats-eye green vials. Level accuracy of 0.001 in./in.Designed to be hit with the butt of a trowel and by the hardened steel trowel blade, this level has a tough aluminum frame with two strike zones to protect from repeated hits.It features a length of 24 inch.This level has strike zone shields that are designed to be hit with a trowel,and also ideal for small detail work and window returns and is the ultimate level for the professional brick and block layer.Solid acrylic vials features the ultimate durability and precision.