The Rotary Wheel is a wonderful mnemonic device, as you literally see the symbol everywhere, once you are attuned to it.

1. The Four sections between the outside teeth and inside spokes = The Rotary 4-Way Test

2. The Six triangular sections between the spokes = The Six Areas of Focus: Water & Sanitation, Maternal & Child Health, Basic Education & Literacy, Economic & Community Development, Disease Prevention & Treatment, and Peace & Conflict Resolution.

3. The 24 teeth on the outside of the wheel = the words to the 4-Way Test:

Is it the Truth? Is it Fair to all concerned? Will it build Goodwill and Better Friendship? Will it be Beneficial to all concerned?

4. The center keyway = Service Above Self

In engineering circles, it is known that a gear with a keyway is a "working gear," that drives the machine and all the other gears.

So, whenever you see this Rotary wheel, let it be a reminder of these important aspects of Rotary in our daily lives!
 
(From Rot. Evan Burrell's Facebook page)