Features MAIN PURPOSE: The stop collar can be used to fix on different positions of the drill bit to accurately control the drilling depth, stable and flexible in operation. SPECIFICATIONS: Including 7pcs limit rings of different specifications, with multi diameters to meet different drilling control requirements, with good practicability. HIGH CARBON STEEL: These stop collars are made of high carbon steel, with high hardness and strength, not easy to deform, greatly extending the service life. FINE ELECTROPLATING: The stop collar set adopts electroplating process to ensure glossy appearance, no rust or scratch, which are safe and reliable in operation. HIGH EFFICIENCY: The decorative edge of the collar makes it easier for the knob to rotate, the depth can be easily adjusted, greatly improving the work efficiency. Specification: Item Type: Stop Collar Set Material: High Carbon Steel Product Specifications: 1/8in, 3/16in, 1/4in, 5/16in, 3/8in, 7/16in, 1/2in, 2.5mm hex wrench Purpose: Used in gear box assembly, motor base, machine tool, drive shaft, farm tools, medical equipment, paper and steel plant equipment, automobile industry, manufacturing industry, amateur craft industry. Package List:7 x Stop Collars 1 x Hex Wrench 1 x Storage Box Package List 7 x Stop Collars 1 x Hex Wrench 1 x Storage Box