Innovative retractable designThe retractable fountain pen uses a precision spring mechanism to allow the nib to be ejected and retracted with one click, ensuring smooth, lag-free operation.The fully enclosed nib compartment completely isolates the pen from air when retracted, effectively preventing the nib from drying out and allowing for immediate use even after long periods of inactivity.0.38mm Ultra-Fine Nib: The retractable fountain pen features a precision-polished 0.38mm nib, perfect for writing small characters, drawing detailed line art, and annotating.Medium Nib: An additional general-purpose medium nib size is available, perfect for everyday writing, document signing, and other applications. Two sizes are available for one pen, covering a wide range of uses.The nib is treated with anti-scratch paper and constructed from highly elastic stainless steel, ensuring smooth operation and enhanced durability.Ergonomic and practical designIntegrated clip and end-touch button: The clip securely clips to notebooks and pockets. The metal-reinforced button has been tested to withstand tens of thousands of cycles without loosening.Scenario-Specific Performance (Retractable Fountain Pens for Writing)Optimized for office use: The retractable design eliminates the worry of losing the cap, and the retracted nib prevents ink leaks, making it suitable for carrying around or slipping into a briefcase.Enhanced for English calligraphy: The nib's spring adjustment balances smoothness with slight splitting, allowing for elegant writing of varying letter weights.