Miami Electronics, Inc manufacturers all jumpers in our facility, guaranteeing quality control from start to finish. While a lot of companies made their jumpers in the USA, their connectors and cables are imported (mostly from China). We only use the best quality USA made components. We only use genuine Amphenols PL259s and our RG213 is made by General Cable. The Heat shrink tubing used is built with an adhesive inner wall which melts and flows, sealing against moisture and water or other contaminants.