4 Piece Set. 3 x high accuracy box levels and 1 x torpedo level for hands-free working. Supplied in a nylon bag. Specifications: Box level: Thickness: 1.4-1.5mm. Accuracy: 0.5mm/m. 2 milled surfaces. Torpedo level: Thickness: 1.3mm. Accuracy: 0.5mm/m. Non-magnetic V-groove.