Features: ● High efficiency: ince there are complete and evenly ditributed particle on the tip, thee file can make the chain conitent and efficient. In jut a few minute, you can eliminate the annoying for harp edge once and for all. ● Durable: The tronget titanium-coated diamond grinding wheel we manufacture ha high hardne and i not eay to deform. It ue a titanium- plated proce, which mean that compared with other drill bit that are not titanium-plated, the ervice life of thee drill bit will be extended by 20%. ● Eay to ue: Thee drill bit are pecially deigned for harpening electric chain . By the way, thee titanium-coated file have a harder nature, which reduce the number of time you need to replace them. ● uitable for ：chain chain polihing, jade, jade gla, etc. ● Note: The diameter of the electric chain i generally 4mm; the diameter of the mall chain i generally 4.8mm. Large chain generally chooe diameter 5.5mm. Specifications: Material: Emery Color ：Golden/ilver ize: Approx. 4/ 4.8/ 5.5mm；0.15/0.18/0.21inch Package Includes: 12x Chain File note: 1.Pleae allow 1-2mm error due to manual meaurement, make ure that you do not mind before you order. 2.Due to the difference between different monitor, the picture may not reflect the actual color of the item.