Manufacturing process keeps improving. Injection molding process is one of the most commonly-used manufacturing process at producing products that made from plastics. From the products that have been designed from the previous final task, injection molding simulation by using software is applied with parameters that have been determined. From the simulation result, parameter with the best quality prediction value is chosen. If there is a product that does not meet the quality prediction requirements that have been determined before, then improvements by changing layout of injection molding or modifying the design from product are taken. From the first simulations that have been carried out, the runner layout and gate design I diameter 4 mm are the best parameters for Carabiner body products. With a quality prediction value of 100%. While design 1 diameter of 6 mm has a quality prediction below 80%, with a value of 79.29% while design I diameter 2 mm, design 3 diameter 2 mm and design 2 diameter 4 mm did not show the quality prediction