The Sealey AK11000 Precision Steel Square Set has been hardened, tempered and precision polished  The Sealey AK11000 is a 4 piece set of Steel Precision Squares that have been hardened, tempered and precision polished. With a quality-made solid steel construction and blade edges and stock face to within ±0.016mm tolerance. Features:   Quality made solid steel construction  Hardened, tempered and precision polished  Blade edges and stock face to within ±0.016mm tolerance   Comes With:   Wooden case  Precision Squares: 50, 75, 100, 150mm  Specification:  Model No: AK11000