The very best transmission selection is when higher transmission reduction is needed. A worm gear is similar to a helical gear with a throat lower to enhance the outer diameter of the wheel. The throat allows the worm gear to wrap entirely close to the threads of the worm. By slicing the threads on the worm instead than the enamel, and by adjusting the variety of threads, various ratios can be achieved without altering the mounting arrangement. A unique attribute of worm gears and worm equipment assemblies is their capability to prevent reverse rotation.