# item.guide
Side-by-Side Comparison Pens, Inks & Leads

D1 Mini Refill vs. Schmidt Euro Rollerball Refill

Comparing 2 standards across 12 specifications. 12 key differences identified.

Comparing:
D1 Mini Refill
Schmidt Euro Rollerball Refill

The D1 Refill (standardized under ISO 12757-1 as Type D) is a standardized miniature metal-cased ballpoint/gel refill measuring exactly 67.0 mm in length and 2.35 mm in diameter. Friction-fit into internal selector sleeves, it is the universal standard for multi-function pens (3-in-1, 4-in-1), compact pocket pens, and precision stylus combinations.

View full D1 Mini Refill spec sheet →

The Euro-Format Rollerball Refill (standardized under DIN 16554 and defined by the Schmidt Safety Ceramic 888/5888 format) is the industry benchmark for luxury capped liquid-ink rollerball pens. Measuring 110.6 mm in length and 6.2 mm in barrel diameter with a ceramic ball tip, it is utilized across hundreds of fine writing brands.

View full Schmidt Euro Rollerball Refill spec sheet →

Specification Comparison Table

12 Parameters
Parameter / Spec
Overall Length
67.0 ± 0.5 mm (2.64 in) 110.6 ± 0.3 mm (4.35 in)
Outer Tube Diameter
2.35 ± 0.05 mm (0.093 in)
Mounting Mechanism
Friction-fit slide sleeve (no threads or springs attached to refill body)
ISO Standard Code
ISO 12757-1 Type D
Ink Varieties
Hybrid low-viscosity (Uni Jetstream SXR-200), Gel (Zebra JSB), standard ballpoint (Lamy M21, Schmidt 635)
Benchmark Multi-Pens
Lamy 2000 4-Color, Rotring 600 3-in-1, Zebra Sharbo X, Kaweco Liliput ballpoint
Barrel Diameter
6.2 ± 0.1 mm (0.244 in)
Tip Collar Diameter
2.5 mm extending 19.5 mm from shoulder
Ball Material
Sintered ceramic ruby ball (0.5 mm Fine, 0.7 mm Medium, 1.0 mm Broad)
Safety Ceramic Venting
Schmidt extended cap-off time technology prevents tip drying for up to 1 year uncapped
Refill Barrel Variants
Schmidt 888 (plastic tube) / Schmidt 5888 (metal casing)
Brand Compatibility
Pelikan, Faber-Castell, Visconti, Kaweco, Retro 51, ACME Studio, OMAS