#100H heavy connecting links are also commonly referred to as #100H master links. Connecting links are commonly used for connecting two ends of the roller chain together. Connecting links are good to have on-hand because they can keep you out of a down situation, and they are good for making miscellaneous repairs to the roller chain. These connecting links exceed in quality, durability, and overall strength. Premier Series #100H Heavy connecting links feature heat-treated components, wide contour side plates, shot peened components, and the side plates are Heavy Duty. These Connecting links are manufactured specifically for #100H heavy roller chain. For more information or if you have any questions please call us or email us, and we will be happy to assist you.