Description: 18 different sizes, 225 pieces. Storage case organizer included, convenient to storage. Abrasion resistant, suitable for high dynamic loads. Use for personal and professional workshops, garages, and plumbing services. Widely used in automobile, mechanical equipment, engineering machinery, chemical, ship, hydropower station, aviation field, can be used for equipments like pump, hydro-cylinder or other hydraulic application that need to seal, to avoid leakage and make the machines work for long time. Specification: Color: Black Size types: 18 20 pieces per size:3x1mm,4x1mm, 4.2x2mm, 5x2mm, 6x2mm, 6x2.5mm, 6x3mm, 7x2mm, 8x2mm 5 pieces per size: 9x2mm, 10x2mm, 12x2mm, 13x1mm, 14x2.5mm, 17x2.5mm, 18x4mm, 20x2mm, 22x2mm Material: rubber Box size (L*W*H): 20.5x10.3x3cm/8.07"x4.06"x1.18"(approx) Quantity: 1 set (225 pieces) Package Includes: 1 x Set Rubber O Ring