Snap hook carabiners are commonly used with a variety of products including ropes, chains, straps, etc. A perfect all purpose hardware item! Our carabiners are made from heavy duty silver zinc plated steel. Latch pushes in to open and closes automatically by a spring. Interlocking teeth prevent the hook from being forced open. Overall length: Approximately 3.93701" (100mm). Opening space when latch is open: Approximately 0.511811" (13mm). DO NOT use this product for overhead lifting, cargo control, or climbing applications!