The best transmission decision is when high transmission reduction is needed. A worm gear is related to a helical gear with a throat lower to improve the outer diameter of the wheel. The throat permits the worm equipment to wrap fully about the threads of the worm. By slicing the threads on the worm rather than the teeth, and by changing the quantity of threads, different ratios can be attained with out altering the mounting arrangement. A distinctive feature of worm gears and worm equipment assemblies is their capacity to prevent reverse rotation.