2 Sizes: The Package Contains 6 Pieces of Dumbbell Collars, Including 4 Pieces of Spring Lock Collars In 25 Mm / 0.984 Inch Inner Diameter for Smooth Barbell Bars, 2 Pieces Dumbbell Collars In 24 Mm / 0.945 Inch Inner Diameter for Threaded Dumbbells, Different Sizes Are Suitable for Different Dumbbells.Please Check Carefully Before Buying The Size and Type of Your Barbell. Quality Material: The Spring Clip Collars Are Made of Quality Steel to Ensure Durability and Reliability. They Are Rustproof and Sturdy, Not Easy to Break or Deform, and Can Serve You for A Long Time. Easy to Hold: Each Spring Clip Comes with A Smooth Handle That Is Easy and Convenient to Hold. The Spring Clip Collar Is Also Easier to Attach and Remove From The Barbell. This Saves You A Lot of Effort and Allows You to Apply It Easily. Safe Training: Our Barbell Collar Can withstand A Lot of Weight and Movement, Making It Ideal for Weightlifting and Strength Training. Suitable for Both Home and Fitness Use, It Will Help You Stay Safe When You Train Fast and Powerful without Worrying About Weights That Move During Exercise or Suddenly Drop. Easy to Handle: The Spring Collars Can Move Your Weight Plates Quickly and Easily, Can Hold The Dumbbells Safely and Securely While Lifting, You Just Have to Loosen and Fasten Them Quickly So That You Can Slide Up and Down Easily When Changing Weights.