as the tooth are angled, they run Considerably quieter than the more inexpensive straight-Slice metal gears. It took me a while to discover this tear-down pic verifying the gears were helical. Pic courtesy of the https://shaunakxpm806637.digiblogbox.com/54337991/the-fact-about-yellow-jacket-sting-hot-to-touch-that-no-one-is-suggesting