The new model has the same basic design but it can be differentiated from the original by the metal tip protector and new body colors, like a pink, neon green, and light blue.

The One F has an improved pigmented ink with a darker black tone and more vibrant colors on the other inks.

As of November 2021 the pens were starting to become available through specialty retailers but were still generally hard to find. They are sold in 0.38 mm and 0.5 mm sizes, like the original, in all the normal colors but none of the limited editions. 

The pen has a cool design, but its main selling point is a pigmented ink which will be sold with a set of new refills in the “UMR” family. 

The UMR refills are generally seen in Uni’s Signo pens, but to date they have been non-pigmented inks. 

The pigmented inks have darker colors and water-resistance that normal gel inks can’t match.

Uni asserts that darker colors are easier to read and create writing that is more memorable than lighter colors.