AIHAO four-color gel pen, multi-color all-in-one, special push pen for students and teachers to take notes in their notebooks [four-color academic master pen] 2 pieces in white

**Product Specifications:**

**Brand:** AIHAO

**Product Name:** MARKKEYPOINTS 4-in-1 Neutral Pen

**Features:**

– Multi-core usage

– Non-slip pen grip

– Easy core switching

– Ideal for marking key points

– Four colors available for easy switching

– Suitable for both left and right brain memory

**Color Psychology:**

– Black: Used for normal tasks

– Red: Ideal for marking mistakes and corrections (increases alertness)

– Blue: Used for recording unmastered content and knowledge points (calming effect)

– Green: Used for recording problems and solutions (boosts positive emotions)

**Tip Size:** 0.5mm for black, blue, red, and green

**Refill Replacement:** Easy and eco-friendly

**Comfortable Grip:** Anti-slip design for pleasant writing experience

**Smooth Core Switching:** Quick and responsive for convenient daily use

**Transparent Pen Clip:** Easy to carry in books or pockets

**Product Parameter:**

– Brand: AIHAO

– Model: GP2470

– Length Calculation: (n-2) x 180°

– S Sector: S = nÏ€R²/360 = LR/2

– Internal and external tangent lines

– Distance between two circles: D = 7R + r (R + Y)

– Intersection of two circles: d = R + r (R – r)

– Inner tangent: R – r ≤ d ≤ R + r

– Diameter: 45mm

– Inner circle: 18mm

– Pen Name: GP2470 Study Pen

– Shell: Transparent, white

– Refill Colors: Black, red, blue, green

– Pen Size: 145mm x 18mm