DIYers and mechanics, this shaft collar set is about to become your new best friend! This 10-piece collection includes electroplate ferronickel collars with M3 locking holes that provide secure positioning for shafts and steel wires. The carbon steel hex fixed buckle design means you can use them repeatedly without breaking - these aren't flimsy cheap collars! The pattern on the knob makes rotation easier when tightening or adjusting, and the plating process prevents rust and scratches for long-lasting performance. Perfect for blocking positions on wheels, axles, or any rotating shaft to prevent slipping or detachment. The set includes various sizes to handle different projects: inner diameters of 4.1mm, 5.1mm, 6.1mm, and 8.1mm with corresponding outer diameters from 9mm to 12mm. Each collar is 5mm thick and comes with the hex wrench you need for installation. Whether you're working on RC cars, machinery, furniture, or any project requiring precise shaft positioning, these collars deliver professional results without the professional price tag. The quality construction means they won't strip or loosen over time, giving you reliable performance project after project.