Mechanical Pencil

1. Shape of Pencil

1.1. Triangle

1.2. Circular

2. Length of Pencil

2.1. Short

2.2. Medium

2.3. Long

3. Refill Method

3.1. Disassemble to insert lead

3.2. Put lead through tip

3.3. Refill through eraser hole

4. Lead Holder

4.1. Multiple lead tubes

4.2. Single tube with lead

4.3. No tube; lead holder

5. Lead Pusher

5.1. 3 separate pushers

5.2. Single adjustable pusher

5.3. 3 inline pushers

5.4. No pusher

6. Eraser

6.1. Twist-out

6.2. Static

6.3. None