since the tooth are angled, they operate A great deal quieter than the greater inexpensive straight-Reduce steel gears. It took me a while to find this tear-down pic verifying the gears had been helical. Pic courtesy of https://tamzinueeb487425.worldblogged.com/34761082/the-fact-about-yellow-jacket-sting-hot-to-touch-that-no-one-is-suggesting