Product advantages: 1.Full range specifications. Free collocation, according to your needs to buy the corresponding specifications. 2.The overall smooth. Smooth surface without burr, high quality workmanship, quality assurance. 3.The selection of high-quality materials. Using high quality material, hardness is harder, no deformation. 4.Deep thread. Clear and complete thread, high performance, high reliability and durable. 5.Quick delivery. 3-5days for the stock items. 6.Third-party inspection before delivery is available.