Circuit Board

There are 3 tiers of the circuit boards. Technically there are 4, but the last one is called the Quantum Manipulator. All say "Circuit Board" as the item name, but they also have a tool tip saying which tier they are. The 3rd one has an extra line that says "PCB", meaning "Printed Circuit Board" because it is made with the Microchip and it's pretty much a basic CPU at that point.

All textures are actually 32 x 32 instead of 16 x 16. This is how it has so much detail. They all use the basic shape, but have color changes.

Trivia

 * Technically there's a 4th tier, but it's called "Quantum Manipulator" instead of circuit board.
 * These are actually 32 x 32 texture size instead of 16 x 16. This is how they have so much detail.
 * They all use the basic shape in the texture.