Feature●【EXCELLENT PERFORMANCE】This Stop Collar Set is designed for Prevent over drilling, is an ideal tool for repeated hole depths.●【EASY TO USE】Flexible positioning, convenient installation and advanced technology. Quick and easy adjustment at any point on drill bit flutes / shafts.●【SPECS】8PCS Aluminum Stop Collar:1/2", 7/16”, 3/8”, 5/16”, ¼”, 7/32”, 3/16”, 1/8”.●【HIGH TENSILE Aluminum STRUCTURE】These Aluminum Stop Collar Set are made from premium steel & aluminum, rust-resistant, corrosion-resistant. Designed using state-of-the-art technology with the client in mind. It will meet your needs and provide excellent quality at an affordable cost.●【SATISFACTION GUARANTEE】 We provide professional and sincere services to escort your shopping. If you are not 100% satisfied with our products, you only need to return them within 30 days to get a full refund. Supports a 12-month warranty.Description