#1 Exhaust flappers
Exhaust flappers are just flat caps that sit on top of exhaust outlets and are attached to the pipes by hinges. The idea is that when there’s sufficient gas pressure from the engine pushing exhaust out, the flap lifts to allow the gases to escape. When there isn’t, the flap closes under its own weight, preventing rain from getting into the exhaust pipes and causing rust and other havoc. My favorite time is when the engine is idling and the flap bobs up and down going “tink! tink!” every time it shuts. :3
Dipper wells are small vessels for rinsing restaurant serving utensils. There is a continuous stream of water running into a slowly-draining basin such that the utensils are constantly submerged in fresh water. They’re commonly used in ice cream parlors and coffee shops. They’re just freaking awesome!