The Nite Ize S-Biner's® are made of high quality, weather-resistant, stainless steel. They have dual gates so that you can secure items to a key-ring, zipper pull, "D" rings, and many other places. They can be linked together or you can attach to the center bar for added security! They are available in three sizes: The first size is #1 and is 1.56" long with a 5 lb. weight rating. The second size is #2 which is 2" long with a 10 lb. weight rating. WARNING: These are not for use where disengagement could result in bodily injury or property damage. Not for climbing!