From the manufacturer:
Hard & Soft 2 Pack: Contains both the soft and hard tip Fudenosuke Brush Pens. Features a flexible brush tip for different lettering and drawing techniques. Create extra-fine, fine or medium strokes by a change in brush pressure. Great for calligraphy and art drawings. Soft tip and hard tip- water-based, pigmented black ink. Odorless. Non-refillable.
Pastel 6 pack: Features a flexible brush tip for different lettering and drawing techniques. Create extra-fine, fine or medium strokes by a change in brush pressure. Great for calligraphy and art drawings. Barrels are made of recycled polypropylene plastic. Water-based, pigmented ink. Odorless. Non-refillable.
Color 10 Pack: Flexible brush tips allow easy transition from thick to thin lines by changing pen pressure. Water-based pigment ink allows rich vibrant colors that won't bleed through most papers. Great for beginner brush calligraphy, hand lettering and illustration. Non-refillable. Contains 10 hard tip Fudenosuke Brush Pens. Colors include: Black, Gray, Red, Orange, Yellow, Green, Blue, Purple, Pink and Brown.