The Techlogix S1-LCA-F-LCA-F is a simplex single mode OS2 female LC/APC to female LC/APC fiber optic coupler. Fiber couplers (sometimes called adapters) are a simple and stable way of extending your fiber optic cable, or creating a service point at a patch panel. These are also great for coupling your bulk fiber installation cable to a patch cable which will increase the longevity of the install cable.