KACO KEFILL Large Capacity Gel Pen Refill ST Tip 0.5mm Black (Single Bagged, Compatible with Click Jumbo) 5-Pack Color Box

Writing endurance equivalent to completing 45 essays of 800 words each or running 4.5 laps around a standard school track.

Equipped with a dual-ball ST precision tip for smooth, stable, and fine writing experience.

Innovative dual-ball technology ensures smooth ink flow and reduces ink skipping.

ST fine tip offers enhanced elasticity for a comfortable writing feel.

Quick-drying ink that prevents smudging and keeps paper clean.

Ink is water-resistant and lightfast, with rich and clear color suitable for marking and correction.

Tested under national standard GB/T37853-2019, with actual line length reaching 1800 meters ±10%.

Compatible with JUMBO Jumbo Click Series pens, including PANTONE and SMILEYWORLD co-branded editions.

Writing angle optimized at 48°, allowing smooth writing even at lower angles compared to typical single-ball tips requiring ~60°.

Writing performed at a 65°-70° angle with a 70mm/s stroke speed over 100mm.

After 3 seconds, a sheet of the same paper type is pressed onto the writing surface and held for 1 minute before separation.

No ink transfer observed on the overlay paper, confirming quick-dry performance.

Test paper complies with GB/T12654 standard.

Ideal for exams, note-taking, marking, and correction.

Reliable for important tests due to clear, computer-recognizable handwriting.

The refill supports long-lasting writing without interruption.

Provides a new level of writing experience through continuous innovation and self-developed dual-ball ST refill technology.