●Material: made of alloy material, it has the characteristics of strong hardness, strong wear resistance, corrosion resistance and soft contact. It is a durable product. ●Compatibility: 2-in-1 4.0mm easy file compatible with Stihl 56057504303 ●Size: 4.0mm ●Product advantages: you can use a chain sharpener to polish the chain without removing the chain. This will save you time and will maintain the efficiency of the chain. ●Good design: this practical chainsaw file comes with a handle design, which is easy to operate, allowing users to operate directly on the chainsaw without hurting their fingers, doing their best to provide customers with satisfactory service.