Product Name: Transmission Tower Hex Anti-Theft Locking Nut with Spring and Ball Model NO.: M16 Grade: 5.6 Standard: DIN, ANSI, GB, JIS, GOST, BSW Head Style: Hexagonal Connection: Common Bolt Type: Hexagon Head Material: Carbon Steel Trademark: xcyc Transport Package: Wooden Boxes with Jute Bag Origin: China HS Code: 731816 Product Description Product specification:product namehex anti-theft locking nut with spring and ballsizeM12~M24materialcarbon steelfeaturehigh quality material, long reinforcement& anti-corrosion timeapplicationOutdoor public facilities against bolt loosening and sabotagepls noted: other sizecan be customed.anti-theft nut benefical:it not only can help you to solve this headache problem,but also help yousave the expensive maintenace charge.For more details information or loosening problems . just contact me as follow, our professional team can help u.