this is a 3 speed manual gearbox it has slow, medium, fast, and neutral. It is very compact. I cant have instructions because it was built specifically for and built into a model I am working on. if you think you can replicate it just ask for some more pics and I will give them.

Step 1: Power Flow

this is where the power goes.

Step 2: Shifting Gears

to shift this all you need to do is move the Orange rod.
picture 1: high gear
picture 2: mid gear/motor speed
picture 3: low gear
picture 4: neutral
picture 5: secondary neutral