**Product Specifications:**
**Brand:** STABILO
**Models:** STABILO EASYbud, STABILO EASYbu, STABILO EASYbuC
**Features:**
- Corrects grip posture from an early age
- Ergonomic pen grip zone designed for correcting children's grip posture
- Ensures long-lasting writing comfort with PPE material pen grip zone
- Unique pen grip centerline to remind children to hold the pen correctly
- German unique spring pen cap design to prevent ink from drying out
- Easy ink refilling with ink sac on the pen body
- Fashionable two-tone pen body design with semi-transparent frosted finish
- Tip options: EF tip (approx. 0.5mm), A tip (approx. 0.6mm), M tip (approx. 0.7mm)
**Usage Tips:**
- Ink sac pens may leak under high pressure conditions like during flights
- Pens may leak ink after intense shaking or vibration, not a product quality issue
- Repeatedly disassembling and assembling ink sacs while in use may cause leaks, not a pen quality issue
**Recommended Users:**
- EF tip: beginners for fine strokes and detailed writing
- A tip: suitable for writing and practice
- M tip: ideal for learners and beginners
**Quote:** "Writing good characters is a lifelong treasure!"
(Note: The provided text contains some errors and incomplete sentences, so the specifications are based on the information provided.)